Amrit Chaudhuri <p><h2>General Info</h2><br><p> <a href="#faq1">How do I place my order?</a><br> <a href="#faq2">How do I check the status of my order?</a><br> <a href="#faq3">What if I need a common peptide available in most catalogs?</a><br> <a href="#faq4">Can you make cGMP peptides?</a><br> <a href="#faq5">Can I have special vialing?</a><br> <a href="#faq6">What if I need to make peptide-based antibodies?</a><br><p><br> <h2>Custom Peptide Design and Production</h2><br><p><br> <a href="#faq7">What do I do with the C-terminus and N-terminus of my peptide?</a><br> <a href="#faq8">What purity should I choose for my research?</a><br> <a href="#faq9">What is the Maximum Peptide Length you can produce?</a><br> <a href="#faq10">Do I need Amino Acid Analysis?</a><br> <a href="#faq11">Do I need Amino Acid Sequencing?</a><br> <a href="#faq12">How can I find the Net Peptide Content?</a><br> <a href="#faq13">What are Peptide Arrays and how can I use them?</a><br> <a href="#faq14">What are Peptide Libraries and how can I use them?</a><br> <a href="#faq15">What is PEGylation and how can I use it?</a><br> <a href="#faq16">How is KLH-Peptide conjugation useful?</a><br> <a href="#faq17">How is BSA-Peptide conjugation useful?</a><br> <a href="#faq18">What is PNA, and can you design and synthesize PNA sequences?</a><br> <a href="#faq19">Can you make PNA-Peptide Conjugates?</a><br><p><br> <h2>Peptide Chemistry</h2><br><p><br> <a href="#faq20">What is the other 10% in a 90% pure peptide?</a><br> <a href="#faq21">What is Net Peptide Content?</a><br> <a href="#faq22">Peptide Purity vs. Net Peptide Content</a><br> <a href="#faq23">How should I store my peptides?</a><br> <a href="#faq24">Can I store peptides in solutions?</a><br> <a href="#faq25">How do I reconstitute my peptides?</a><br> <a href="#faq26">Why does solubility vary amongst peptides?</a><br> <br><p><h2>General Info</h2><br><p> <dl> <h2 class="faq_question" id="faq1">How do I place my order?</h2> <p class="faq_answer">Advanced Peptides offers 3 ways to order your products: <ul> <li>Email us at <a href="mailto:sales@advancedpeptides.com">sales@advancedpeptides.com</a></li> <li>Call us at (617) 562-5740</li> <li>Download an order form and fax it to us at (617) 562-5745</li> </ul></p> <h2 class="faq_question" id="faq2">How do I check the status of my order?</h2> <p class="faq_answer">Feel free to contact our customer service department by email at <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or by phone (617) 562-5740 during normal business hours for information on the status of your order.</p> <h2 class="faq_question" id="faq3">What if I need a common peptide available in most catalogs?</h2> <p class="faq_answer"> While we are a custom peptide & PNA synthesis company, we actually supply many companies with bulk peptides for retail. If you are interested in a particular peptide, feel free to inquire with our sales staff, and we may be able to sell you the peptide directly at wholesale price. </p> <h2 class="faq_question" id="faq4">Can you make cGMP peptides?</h2> <p class="faq_answer">Advanced Peptides offers cGMP peptides for use in clinical trials or for FDA regulated drug production. We have a dedicated state-of-the-art multi-gram to kilogram cGMP facility. Please call or email and inquire if you have any questions regarding GMP orders or procedures. Email us at <a href="mailto:sales@advancedpeptides.com">sales@advancedpeptides.com</a> P: (617) 562-5740.</p> <h2 class="faq_question" id="faq5">Can I have special vialing?</h2> <p class="faq_answer">Advanced Peptides offers our customers a vialing service, allotting prepackaged amounts of your peptides into multiple vials to help ease research, as well as use in redistribution. Please contact our sales department for further information.</p> <h2 class="faq_question" id="faq6">What if I need to make peptide-based antibodies?</h2> <p class="faq_answer">Peptides are regularly designed for antibody production. If you are unsure of where to go for your antibody production, we can recommend multiple high quality labs that specialize in antibody production.</p> </dl> <br><p><h2>Custom Peptide Design and Production</h2><p><br> <dl> <h2 class="faq_question" id="faq7">What do I do with the C-terminus and N-terminus of my peptide?</h2> <p class="faq_answer"> <p>While there are a lot of novel peptide designs, most biologically active custom peptides are designed to mimic proteins or cleaved protein products. When proteins are cleaved in vivo, they have naturally occurring unprotected termini. Blocking these sequences is not necessary. When the sequence is not a known cleavage product blocking the termini is necessary in order to mimic the peptide bonds normally found in the parent sequence.</p> <p>The general rule for determination of peptide terminus blocking is the following:</p> <ul> <li>When the peptide sequence is derived from the C-terminal section of a protein, block the N-terminus by acetylation.</li> <li>When the peptide sequence is derived from the N-terminal section of a protein, block the C-terminus by amidation.</li> <li>When the peptide sequence is internal, block both ends with acetylation and amidation.</li> </ul> <p>However, this is a very general rule. We highly recommend calling or emailing our technical staff for further consultation on the specific sequence and intended use: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> </p> <h2 class="faq_question" id="faq8">What purity should I choose for my research?</h2> <p class="faq_answer">The right choice of purity is very important for the success of your experiment. Depending on what you intend to do with your peptides, this choice varies. Common uses for peptides are non-sensitive assays, immunogen research, antibody production, receptor/ligand studies, bio-assay studies, cell studies, and structural studies. <ul> <li><em>Non-sensitive screening assays:</em> We recommend a peptide purity of >75%. This should be sufficient for screening.</li> <li><em>Antibody producing/Immunogen grade peptides:</em> We recommend a minimum peptide purity of 85%. Generally we encourage >90% purity in the peptides. Increasing the purity of these peptides improves the immunological response and the production of specific, high-titer antibodies.</li> <li><em>Receptor/Ligand Studies, bio-assay studies, and cell studies:</em> We recommend a peptide purity of >95% for accurate research results. These also benefit from >98% purity peptides in producing better-defined research results.</li> <li><em>Structural studies:</em> We recommend >98% for all structural studies.</li> </ul> </p> <h2 class="faq_question" id="faq9">What is the Maximum Peptide Length you can produce?</h2> <p class="faq_answer">Advanced Peptides routinely produces peptides of >70 amino acids in length. We can also produce peptides of greater than 100 amino acids in length.</p> <h2 class="faq_question" id="faq10">Do I need Amino Acid Analysis?</h2> <p class="faq_answer">Most custom peptides do not require an Amino Acid Analysis as you can determine most of the crucial information from an HPLC trace and Mass Spec analysis. In cases where the net peptide content determination is required, or other information needs to be ascertained, we provide amino acid analysis for a fee.</p> <h2 class="faq_question" id="faq11">Do I need Amino Acid Sequencing?</h2> <p class="faq_answer">Under solid phase synthesis peptides are produced in a controlled and calculated environment. There are very few occasions that the peptide sequence is in question. By using a mass spec analysis, you can determine the molecular weight of the peptide, thus proving the sequence completion of the synthesis. However, there are cases where sequencing is something we recommend, such as with MAPS peptides. With the majority of MAPS peptides, the mass spec analysis provides inconclusive information, because of the nature of MAPS peptides. Sequencing can be an easy alternative for proof of synthesis completion, and affirmation of peptide sequence in publication use.</p> <h2 class="faq_question" id="faq12">How can I find the Net Peptide Content?</h2> <p class="faq_answer">Net peptide content is determined with an Amino Acid Analysis.</p> <h2 class="faq_question" id="faq13">What are Peptide Arrays and how can I use them?</h2> <p class="faq_answer">Peptide Arrays are the production of a large number of peptide sequences (minimum 96 peptides) for use in high throughput screening. We can produce peptides of up to 18 amino acids in length at a 2.5 µmol, 5 µmol, and 10 µmol scale. Arrays can be used for epitope mapping, peptide libraries, protein characterization and much more. Our arrays start at only $29/peptide. </p> <h2 class="faq_question" id="faq14">What are Peptide Libraries and how can I use them?</h2> <p class="faq_answer"> <p>A Peptide library is the systematic combination of different peptides in large numbers. It has proven to be a powerful tool for drug discovery, structural studies and other applications.</p> <p>Some common applications of a peptide library are as follows: description of variations of antibody specificity (epitopes), identification of bioactive peptides and ligand-binding activities, the generation of synthetic vaccines and antimicrobial peptides, as well as purification of peptides.</p> <p>One of the advantages of peptide libraries prepared by solid phase synthesis is that the peptides can remain on a solid support. Detection of specific peptides can be done via standard immunological enzyme staining methods, and are then manually separable under microscopy to determine the peptide sequences directly. For libraries, we are able to offer the following: Keep the peptide on/off the resin, scramble the amino acids, use specific linkers, dye-label, as well as many other modifications.</p> <p>Contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> </p> <h2 class="faq_question" id="faq15">What is PEGylation and how can I use it?</h2> <p class="faq_answer">PEG is an FDA-approved delivery system for peptide and protein-based biopharmaceuticals. PEGyaltion is the chemical attachment of polyethylene glycol (PEG) to a peptide on a specified site on the molecule. Studies have shown an increase in the potential bioavailability of peptides when incorporating PEG into peptide sequences versus the injection of a naked peptide. Drug oriented peptides show significant improvement to their therapeutic properties, including better patient compliance and side effect profile. For more information contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> <h2 class="faq_question" id="faq16">How is KLH-Peptide conjugation useful?</h2> <p class="faq_answer"> <p>Keyhole Limpet Hemocyanin (KLH) is a commonly used carrier protein in the conjugation of peptides for antibody production. It is an immune-modifying carrier that increases the efficacy of peptides in therapeutic vaccines. A protein from the hemocyanins grouping, KLH is isolated from the mollusk Megathura crenulata and further developed and purified under cGMP procedures. Its use as a potent immunogenic carrier protein stem from its high molecular weights, potent T-cell epitopes, and multiple sites for high-density antigen conjugation. For more information contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> </p> <h2 class="faq_question" id="faq17">How is BSA-Peptide conjugation useful?</h2> <p class="faq_answer"> <p>Bovine serum albumin (BSA) is a commonly used carrier protein in the conjugation of peptides for antibody production. Albumins make up about half of the protein in plasma and are the most stable and soluble proteins in plasma. It is very popular with laboratories developing immunoassays, mostly due to its availability, solubility and the numerous functional groups present for coupling to heptans.</p> <p>When compared to KLH, another common carrier, the molecular weight of BSA is much smaller. However, BSA is much more soluble and immunogenic. It contains 59 lysines, 30-35 as primary amines capable of reacting with conjugation sites of linkers. It is a popular carrier for weakly antigenic compounds. BSA can be used to block nonspecific binding sites in many immunochemical experiments such as ELISA, immunoblotting and immunohistochemical studies. It may be used as a non-relevant protein in enzyme immunoassays. KLH cannot be used for this because the anti-KLH antibodies, which formed during immunization, will interfere with the measurement of anti-heptan antibodies. When KLH is used as the carrier, heptan-BSA conjugates can be used because they do not interfere with the measurement for anti-heptan antibodies. For more information contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> </p> <h2 class="faq_question" id="faq18">What is PNA, and can you design and synthesize PNA sequences?</h2> <p class="faq_answer"> <p>Peptide nucleic acids (PNA) are structures that mimic DNA and RNA. They replace the phosphate-sugar backbone with a backbone based on amino acids. The loss of the charged phosphate group in the backbone eliminates electrostatic repulsion in binding, allowing PNAs to bind to DNA and RNA with higher affinities than unmodified DNA. They are resistant to nuclease and protease degradation and thus provide promising opportunities in diagnostic and biomolecular probes, as well as antisense and antigene drugs. </p> <p> We can help you design a pure PNA sequence, or help integrate and implement it into an existing polypeptide design. For more information contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740. </p> <h2 class="faq_question" id="faq19">Can you make PNA-Peptide Conjugates?</h2> <p class="faq_answer"> <p>We are capable of synthesizing many different types of PNA-Peptide Conjugates. We are capable of inserting a peptide sequence at any part of the larger PNA sequence, and vice versa. Common conjugations are:</p> <br> N-Peptide-PNA-C &nbsp; &nbsp; &nbsp; &nbsp; N-PNA1-Peptide-PNA2-C<br> N-PNA-Peptide-C &nbsp; &nbsp; &nbsp; &nbsp; N-Peptide1-PNA-Peptide2-C<br> <br> <p> As well as many other combinations of Peptides and PNA's. For more information contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740. </p> <br><p><h2>Peptide Chemistry</h2><p><br> <dl> <h2 class="faq_question" id="faq20">What is the other 10% in a 90% pure peptide?</h2> <p class="faq_answer">Peptide Purity is the percentage target sequence amongst the total quantity of peptides. Because peptide bond formation in synthesis is not 100% efficient, not all polypeptide chains are the target sequence. Some chains may not go to completion, or amino acids may not properly bond on certain chains. These deleted sequences make up a certain percentage of peptides in your mixture. We analyze and purify crude peptides using Reverse Phase HPLC in conjunction with Mass Spec Analysis to attain the desired target sequence purity.</p> <h2 class="faq_question" id="faq21">What is Net Peptide Content?</h2> <p class="faq_answer">After your peptide is purified and lyophilized, the white peptide powder will contain some non-peptide components such as water, absorbed solvents, counter ions and salts. Net peptide content consists of the actual percentage weight of peptide in your final product. This number varies, anywhere from 50 to 90 percent, depending on the purity, sequence and method of synthesis and purification. When calculating the concentration of peptide solution for biological assays or other sensitive peptide experiments, it is essential that you account for peptide content. Peptide concentrations can be determined by subtracting away the non-peptide weight determining the volume of solvent in which to dissolve. For example, when using 1mg of final product to make a 1mg/ml solution of peptide with a content of 80%, you would use 800ul of solvent instead of 1000ul.</p> <h2 class="faq_question" id="faq22">Peptide Purity vs. Net Peptide Content</h2> <p class="faq_answer">While they seem similar at first glance, peptide purity and net peptide content describe two different quantitative properties of the final product. Purity is usually determined by Reverse Phase-HPLC in conjunction with Mass Spec Analysis and defines the percent of sample that is the target peptide sequence. Net peptide content only gives information on the percent of peptide versus non-peptide components. Net peptide content is accurately found by performing amino acid analysis.</p> <h2 class="faq_question" id="faq23">How should I store my peptides?</h2> <p class="faq_answer"><ul> <li>Peptides are supplied as lyophilized powder and are often hygroscopic.</li> <li>Place in closed dry environment with desiccants.</li> <li>Upon arrival, store lyophilized peptide in a freezer at -20 degrees C for best results.</li> <li>Ambient temperature during shipping does not affect product life and efficacy.</li> </ul></p> <h2 class="faq_question" id="faq24">Can I store peptides in solutions?</h2> <p class="faq_answer"> <p>It is not recommended to keep excess peptides in solution. The shelf life of peptides in solution is very limited, especially for sequences containing cysteine, methionine, tryptophan, asparagine, glutamine, and N-terminal glutamic acid.</p> <p>If you have to store peptides in solution, use a sterile buffer at pH 5-6 and store at -20C to prolong the storage life.</p> <h2 class="faq_question" id="faq25">How do I reconstitute my peptides?</h2> <p class="faq_answer"> <p>Peptides are generally easy to solubilize. We generally recommend trying to reconstitute your peptide in a small amount of the intended solvent to make sure the peptide solubility is viable. If you don't know the best solution to reconstitute your peptide, or are having solubility issues, use the procedure below, or feel free to contact us at <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> <p><a href="http://shop.advancedpeptides.com/pages/solubility">Solubility Recommendation</a></p> <h2 class="faq_question" id="faq26">Why does solubility vary amongst peptides?</h2> <p class="faq_answer"> <p>Solubility is often a major challenge for researchers who work with peptides. Because each amino acid exhibits unique physical characteristics, each peptide sequence has specific solubility requirements. Amino acids such as leucine, isoleucine, and valine are very hydrophobic. Other amino acids like lysine, histidine, and arginine are hydrophilic.</p> <p>The quantity and sequence in which these amino acids occur in the peptide determines the solubility.</p> 2009-12-28T14:31:05-05:00 faq 3703002 2009-12-28T14:31:05-05:00 382632 2010-01-11T15:17:34-05:00 <notextile> <p><h2>General Info</h2><br><p> <a href="#faq1">How do I place my order?</a><br> <a href="#faq2">How do I check the status of my order?</a><br> <a href="#faq3">What if I need a common peptide available in most catalogs?</a><br> <a href="#faq4">Can you make cGMP peptides?</a><br> <a href="#faq5">Can I have special vialing?</a><br> <a href="#faq6">What if I need to make peptide-based antibodies?</a><br><p><br> <h2>Custom Peptide Design and Production</h2><br><p><br> <a href="#faq7">What do I do with the C-terminus and N-terminus of my peptide?</a><br> <a href="#faq8">What purity should I choose for my research?</a><br> <a href="#faq9">What is the Maximum Peptide Length you can produce?</a><br> <a href="#faq10">Do I need Amino Acid Analysis?</a><br> <a href="#faq11">Do I need Amino Acid Sequencing?</a><br> <a href="#faq12">How can I find the Net Peptide Content?</a><br> <a href="#faq13">What are Peptide Arrays and how can I use them?</a><br> <a href="#faq14">What are Peptide Libraries and how can I use them?</a><br> <a href="#faq15">What is PEGylation and how can I use it?</a><br> <a href="#faq16">How is KLH-Peptide conjugation useful?</a><br> <a href="#faq17">How is BSA-Peptide conjugation useful?</a><br> <a href="#faq18">What is PNA, and can you design and synthesize PNA sequences?</a><br> <a href="#faq19">Can you make PNA-Peptide Conjugates?</a><br><p><br> <h2>Peptide Chemistry</h2><br><p><br> <a href="#faq20">What is the other 10% in a 90% pure peptide?</a><br> <a href="#faq21">What is Net Peptide Content?</a><br> <a href="#faq22">Peptide Purity vs. Net Peptide Content</a><br> <a href="#faq23">How should I store my peptides?</a><br> <a href="#faq24">Can I store peptides in solutions?</a><br> <a href="#faq25">How do I reconstitute my peptides?</a><br> <a href="#faq26">Why does solubility vary amongst peptides?</a><br> <br><p><h2>General Info</h2><br><p> <dl> <h2 class="faq_question" id="faq1">How do I place my order?</h2> <p class="faq_answer">Advanced Peptides offers 3 ways to order your products: <ul> <li>Email us at <a href="mailto:sales@advancedpeptides.com">sales@advancedpeptides.com</a></li> <li>Call us at (617) 562-5740</li> <li>Download an order form and fax it to us at (617) 562-5745</li> </ul></p> <h2 class="faq_question" id="faq2">How do I check the status of my order?</h2> <p class="faq_answer">Feel free to contact our customer service department by email at <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or by phone (617) 562-5740 during normal business hours for information on the status of your order.</p> <h2 class="faq_question" id="faq3">What if I need a common peptide available in most catalogs?</h2> <p class="faq_answer"> While we are a custom peptide & PNA synthesis company, we actually supply many companies with bulk peptides for retail. If you are interested in a particular peptide, feel free to inquire with our sales staff, and we may be able to sell you the peptide directly at wholesale price. </p> <h2 class="faq_question" id="faq4">Can you make cGMP peptides?</h2> <p class="faq_answer">Advanced Peptides offers cGMP peptides for use in clinical trials or for FDA regulated drug production. We have a dedicated state-of-the-art multi-gram to kilogram cGMP facility. Please call or email and inquire if you have any questions regarding GMP orders or procedures. Email us at <a href="mailto:sales@advancedpeptides.com">sales@advancedpeptides.com</a> P: (617) 562-5740.</p> <h2 class="faq_question" id="faq5">Can I have special vialing?</h2> <p class="faq_answer">Advanced Peptides offers our customers a vialing service, allotting prepackaged amounts of your peptides into multiple vials to help ease research, as well as use in redistribution. Please contact our sales department for further information.</p> <h2 class="faq_question" id="faq6">What if I need to make peptide-based antibodies?</h2> <p class="faq_answer">Peptides are regularly designed for antibody production. If you are unsure of where to go for your antibody production, we can recommend multiple high quality labs that specialize in antibody production.</p> </dl> <br><p><h2>Custom Peptide Design and Production</h2><p><br> <dl> <h2 class="faq_question" id="faq7">What do I do with the C-terminus and N-terminus of my peptide?</h2> <p class="faq_answer"> <p>While there are a lot of novel peptide designs, most biologically active custom peptides are designed to mimic proteins or cleaved protein products. When proteins are cleaved in vivo, they have naturally occurring unprotected termini. Blocking these sequences is not necessary. When the sequence is not a known cleavage product blocking the termini is necessary in order to mimic the peptide bonds normally found in the parent sequence.</p> <p>The general rule for determination of peptide terminus blocking is the following:</p> <ul> <li>When the peptide sequence is derived from the C-terminal section of a protein, block the N-terminus by acetylation.</li> <li>When the peptide sequence is derived from the N-terminal section of a protein, block the C-terminus by amidation.</li> <li>When the peptide sequence is internal, block both ends with acetylation and amidation.</li> </ul> <p>However, this is a very general rule. We highly recommend calling or emailing our technical staff for further consultation on the specific sequence and intended use: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> </p> <h2 class="faq_question" id="faq8">What purity should I choose for my research?</h2> <p class="faq_answer">The right choice of purity is very important for the success of your experiment. Depending on what you intend to do with your peptides, this choice varies. Common uses for peptides are non-sensitive assays, immunogen research, antibody production, receptor/ligand studies, bio-assay studies, cell studies, and structural studies. <ul> <li><em>Non-sensitive screening assays:</em> We recommend a peptide purity of >75%. This should be sufficient for screening.</li> <li><em>Antibody producing/Immunogen grade peptides:</em> We recommend a minimum peptide purity of 85%. Generally we encourage >90% purity in the peptides. Increasing the purity of these peptides improves the immunological response and the production of specific, high-titer antibodies.</li> <li><em>Receptor/Ligand Studies, bio-assay studies, and cell studies:</em> We recommend a peptide purity of >95% for accurate research results. These also benefit from >98% purity peptides in producing better-defined research results.</li> <li><em>Structural studies:</em> We recommend >98% for all structural studies.</li> </ul> </p> <h2 class="faq_question" id="faq9">What is the Maximum Peptide Length you can produce?</h2> <p class="faq_answer">Advanced Peptides routinely produces peptides of >70 amino acids in length. We can also produce peptides of greater than 100 amino acids in length.</p> <h2 class="faq_question" id="faq10">Do I need Amino Acid Analysis?</h2> <p class="faq_answer">Most custom peptides do not require an Amino Acid Analysis as you can determine most of the crucial information from an HPLC trace and Mass Spec analysis. In cases where the net peptide content determination is required, or other information needs to be ascertained, we provide amino acid analysis for a fee.</p> <h2 class="faq_question" id="faq11">Do I need Amino Acid Sequencing?</h2> <p class="faq_answer">Under solid phase synthesis peptides are produced in a controlled and calculated environment. There are very few occasions that the peptide sequence is in question. By using a mass spec analysis, you can determine the molecular weight of the peptide, thus proving the sequence completion of the synthesis. However, there are cases where sequencing is something we recommend, such as with MAPS peptides. With the majority of MAPS peptides, the mass spec analysis provides inconclusive information, because of the nature of MAPS peptides. Sequencing can be an easy alternative for proof of synthesis completion, and affirmation of peptide sequence in publication use.</p> <h2 class="faq_question" id="faq12">How can I find the Net Peptide Content?</h2> <p class="faq_answer">Net peptide content is determined with an Amino Acid Analysis.</p> <h2 class="faq_question" id="faq13">What are Peptide Arrays and how can I use them?</h2> <p class="faq_answer">Peptide Arrays are the production of a large number of peptide sequences (minimum 96 peptides) for use in high throughput screening. We can produce peptides of up to 18 amino acids in length at a 2.5 µmol, 5 µmol, and 10 µmol scale. Arrays can be used for epitope mapping, peptide libraries, protein characterization and much more. Our arrays start at only $29/peptide. </p> <h2 class="faq_question" id="faq14">What are Peptide Libraries and how can I use them?</h2> <p class="faq_answer"> <p>A Peptide library is the systematic combination of different peptides in large numbers. It has proven to be a powerful tool for drug discovery, structural studies and other applications.</p> <p>Some common applications of a peptide library are as follows: description of variations of antibody specificity (epitopes), identification of bioactive peptides and ligand-binding activities, the generation of synthetic vaccines and antimicrobial peptides, as well as purification of peptides.</p> <p>One of the advantages of peptide libraries prepared by solid phase synthesis is that the peptides can remain on a solid support. Detection of specific peptides can be done via standard immunological enzyme staining methods, and are then manually separable under microscopy to determine the peptide sequences directly. For libraries, we are able to offer the following: Keep the peptide on/off the resin, scramble the amino acids, use specific linkers, dye-label, as well as many other modifications.</p> <p>Contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> </p> <h2 class="faq_question" id="faq15">What is PEGylation and how can I use it?</h2> <p class="faq_answer">PEG is an FDA-approved delivery system for peptide and protein-based biopharmaceuticals. PEGyaltion is the chemical attachment of polyethylene glycol (PEG) to a peptide on a specified site on the molecule. Studies have shown an increase in the potential bioavailability of peptides when incorporating PEG into peptide sequences versus the injection of a naked peptide. Drug oriented peptides show significant improvement to their therapeutic properties, including better patient compliance and side effect profile. For more information contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> <h2 class="faq_question" id="faq16">How is KLH-Peptide conjugation useful?</h2> <p class="faq_answer"> <p>Keyhole Limpet Hemocyanin (KLH) is a commonly used carrier protein in the conjugation of peptides for antibody production. It is an immune-modifying carrier that increases the efficacy of peptides in therapeutic vaccines. A protein from the hemocyanins grouping, KLH is isolated from the mollusk Megathura crenulata and further developed and purified under cGMP procedures. Its use as a potent immunogenic carrier protein stem from its high molecular weights, potent T-cell epitopes, and multiple sites for high-density antigen conjugation. For more information contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> </p> <h2 class="faq_question" id="faq17">How is BSA-Peptide conjugation useful?</h2> <p class="faq_answer"> <p>Bovine serum albumin (BSA) is a commonly used carrier protein in the conjugation of peptides for antibody production. Albumins make up about half of the protein in plasma and are the most stable and soluble proteins in plasma. It is very popular with laboratories developing immunoassays, mostly due to its availability, solubility and the numerous functional groups present for coupling to heptans.</p> <p>When compared to KLH, another common carrier, the molecular weight of BSA is much smaller. However, BSA is much more soluble and immunogenic. It contains 59 lysines, 30-35 as primary amines capable of reacting with conjugation sites of linkers. It is a popular carrier for weakly antigenic compounds. BSA can be used to block nonspecific binding sites in many immunochemical experiments such as ELISA, immunoblotting and immunohistochemical studies. It may be used as a non-relevant protein in enzyme immunoassays. KLH cannot be used for this because the anti-KLH antibodies, which formed during immunization, will interfere with the measurement of anti-heptan antibodies. When KLH is used as the carrier, heptan-BSA conjugates can be used because they do not interfere with the measurement for anti-heptan antibodies. For more information contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> </p> <h2 class="faq_question" id="faq18">What is PNA, and can you design and synthesize PNA sequences?</h2> <p class="faq_answer"> <p>Peptide nucleic acids (PNA) are structures that mimic DNA and RNA. They replace the phosphate-sugar backbone with a backbone based on amino acids. The loss of the charged phosphate group in the backbone eliminates electrostatic repulsion in binding, allowing PNAs to bind to DNA and RNA with higher affinities than unmodified DNA. They are resistant to nuclease and protease degradation and thus provide promising opportunities in diagnostic and biomolecular probes, as well as antisense and antigene drugs. </p> <p> We can help you design a pure PNA sequence, or help integrate and implement it into an existing polypeptide design. For more information contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740. </p> <h2 class="faq_question" id="faq19">Can you make PNA-Peptide Conjugates?</h2> <p class="faq_answer"> <p>We are capable of synthesizing many different types of PNA-Peptide Conjugates. We are capable of inserting a peptide sequence at any part of the larger PNA sequence, and vice versa. Common conjugations are:</p> <br> N-Peptide-PNA-C &nbsp; &nbsp; &nbsp; &nbsp; N-PNA1-Peptide-PNA2-C<br> N-PNA-Peptide-C &nbsp; &nbsp; &nbsp; &nbsp; N-Peptide1-PNA-Peptide2-C<br> <br> <p> As well as many other combinations of Peptides and PNA's. For more information contact our technical department for design specification: <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740. </p> <br><p><h2>Peptide Chemistry</h2><p><br> <dl> <h2 class="faq_question" id="faq20">What is the other 10% in a 90% pure peptide?</h2> <p class="faq_answer">Peptide Purity is the percentage target sequence amongst the total quantity of peptides. Because peptide bond formation in synthesis is not 100% efficient, not all polypeptide chains are the target sequence. Some chains may not go to completion, or amino acids may not properly bond on certain chains. These deleted sequences make up a certain percentage of peptides in your mixture. We analyze and purify crude peptides using Reverse Phase HPLC in conjunction with Mass Spec Analysis to attain the desired target sequence purity.</p> <h2 class="faq_question" id="faq21">What is Net Peptide Content?</h2> <p class="faq_answer">After your peptide is purified and lyophilized, the white peptide powder will contain some non-peptide components such as water, absorbed solvents, counter ions and salts. Net peptide content consists of the actual percentage weight of peptide in your final product. This number varies, anywhere from 50 to 90 percent, depending on the purity, sequence and method of synthesis and purification. When calculating the concentration of peptide solution for biological assays or other sensitive peptide experiments, it is essential that you account for peptide content. Peptide concentrations can be determined by subtracting away the non-peptide weight determining the volume of solvent in which to dissolve. For example, when using 1mg of final product to make a 1mg/ml solution of peptide with a content of 80%, you would use 800ul of solvent instead of 1000ul.</p> <h2 class="faq_question" id="faq22">Peptide Purity vs. Net Peptide Content</h2> <p class="faq_answer">While they seem similar at first glance, peptide purity and net peptide content describe two different quantitative properties of the final product. Purity is usually determined by Reverse Phase-HPLC in conjunction with Mass Spec Analysis and defines the percent of sample that is the target peptide sequence. Net peptide content only gives information on the percent of peptide versus non-peptide components. Net peptide content is accurately found by performing amino acid analysis.</p> <h2 class="faq_question" id="faq23">How should I store my peptides?</h2> <p class="faq_answer"><ul> <li>Peptides are supplied as lyophilized powder and are often hygroscopic.</li> <li>Place in closed dry environment with desiccants.</li> <li>Upon arrival, store lyophilized peptide in a freezer at -20 degrees C for best results.</li> <li>Ambient temperature during shipping does not affect product life and efficacy.</li> </ul></p> <h2 class="faq_question" id="faq24">Can I store peptides in solutions?</h2> <p class="faq_answer"> <p>It is not recommended to keep excess peptides in solution. The shelf life of peptides in solution is very limited, especially for sequences containing cysteine, methionine, tryptophan, asparagine, glutamine, and N-terminal glutamic acid.</p> <p>If you have to store peptides in solution, use a sterile buffer at pH 5-6 and store at -20C to prolong the storage life.</p> <h2 class="faq_question" id="faq25">How do I reconstitute my peptides?</h2> <p class="faq_answer"> <p>Peptides are generally easy to solubilize. We generally recommend trying to reconstitute your peptide in a small amount of the intended solvent to make sure the peptide solubility is viable. If you don't know the best solution to reconstitute your peptide, or are having solubility issues, use the procedure below, or feel free to contact us at <a href="mailto:tech@advancedpeptides.com">tech@advancedpeptides.com</a> or (617) 562-5740.</p> <p><a href="http://shop.advancedpeptides.com/pages/solubility">Solubility Recommendation</a></p> <h2 class="faq_question" id="faq26">Why does solubility vary amongst peptides?</h2> <p class="faq_answer"> <p>Solubility is often a major challenge for researchers who work with peptides. Because each amino acid exhibits unique physical characteristics, each peptide sequence has specific solubility requirements. Amino acids such as leucine, isoleucine, and valine are very hydrophobic. Other amino acids like lysine, histidine, and arginine are hydrophilic.</p> <p>The quantity and sequence in which these amino acids occur in the peptide determines the solubility.</p> </notextile>