[{"data":1,"prerenderedAt":211},["ShallowReactive",2],{"compound-bacteriostatic-water":3,"compound-related-bacteriostatic-water":203,"compound-reading-bacteriostatic-water":204},{"id":4,"title":5,"alsoKnownAs":6,"body":7,"casNumber":175,"category":176,"description":166,"extension":177,"faq":178,"meta":188,"molecularFormula":175,"molecularWeight":175,"name":5,"navigation":189,"path":190,"presentations":191,"purity":175,"rank":194,"relatedCompounds":195,"relatedResearch":196,"seo":199,"sequence":175,"stem":200,"summary":201,"__hash__":202},"compounds\u002Fcompounds\u002Fbacteriostatic-water.md","Bacteriostatic Water","0.9% benzyl alcohol in sterile water",{"type":8,"value":9,"toc":165},"minimark",[10,15,19,23,26,34,51,55,121,124,128,135,138,141,145,158,162],[11,12,14],"h2",{"id":13},"what-it-is","What it is",[16,17,18],"p",{},"Bacteriostatic water is sterile water for injection containing 0.9% benzyl\nalcohol as a bacteriostatic preservative. Its purpose in peptide work is\nstraightforward: it is the diluent that turns a lyophilised cake into a solution,\nand the preservative allows a vial to be entered more than once without the\ncontents becoming a culture medium.",[11,20,22],{"id":21},"not-an-assayed-peptide","Not an assayed peptide",[16,24,25],{},"This page states the obvious because the market frequently does not.",[16,27,28,29,33],{},"Bacteriostatic water has ",[30,31,32],"strong",{},"no purity specification, no HPLC result and no peptide\nCertificate of Analysis",", because there is no peptide in it to assay. Listings\nthat advertise \"99% purity\" bacteriostatic water are either copying a template\nfrom a peptide product page or inventing a number outright, and it is a useful\ntell about the rest of a vendor's documentation.",[16,35,36,37,40,41,44,45,50],{},"What it does have — and what a supplier should be able to speak to — are\n",[30,38,39],{},"sterility"," and ",[30,42,43],{},"endotoxin"," specifications. Those are the meaningful quality\nattributes for a sterile solvent, and they are established by entirely different\nmethods from the ones used on peptides. See\n",[46,47,49],"a",{"href":48},"\u002Fresearch\u002Fendotoxin-and-sterility-testing","endotoxin and sterility testing",".",[11,52,54],{"id":53},"bacteriostatic-versus-sterile-water","Bacteriostatic versus sterile water",[56,57,58,73],"table",{},[59,60,61],"thead",{},[62,63,64,67,70],"tr",{},[65,66],"th",{},[65,68,69],{},"Bacteriostatic water",[65,71,72],{},"Sterile water",[74,75,76,88,99,110],"tbody",{},[62,77,78,82,85],{},[79,80,81],"td",{},"Preservative",[79,83,84],{},"0.9% benzyl alcohol",[79,86,87],{},"None",[62,89,90,93,96],{},[79,91,92],{},"Vial entries",[79,94,95],{},"Multiple",[79,97,98],{},"Single use",[62,100,101,104,107],{},[79,102,103],{},"Suits",[79,105,106],{},"Solutions stored over days or weeks",[79,108,109],{},"Single-session preparation",[62,111,112,115,118],{},[79,113,114],{},"Consideration",[79,116,117],{},"Benzyl alcohol is an additional variable in the system",[79,119,120],{},"No preservative to interact with the peptide",[16,122,123],{},"The choice is not automatic. Where a reconstituted peptide will be drawn on\nrepeatedly over a period, the preservative is doing necessary work. Where a\nworking solution is prepared and consumed in one session — or where the peptide\nis aggregation-prone and you want the fewest possible variables — a\npreservative-free diluent is the cleaner option.",[11,125,127],{"id":126},"handling-and-storage","Handling and storage",[16,129,130,131,134],{},"Store at controlled room temperature, protected from light. ",[30,132,133],{},"Do not freeze.","\nUnlike lyophilised peptides, there is no benefit to cold storage here and\nfreezing risks the container.",[16,136,137],{},"Inspect before use: the solution should be clear and colourless, with no\nparticulates and no discolouration. Discard any vial that fails that inspection\nregardless of its date. Wipe the stopper before each entry — the preservative\ninhibits growth, it does not sterilise what you introduce.",[16,139,140],{},"Once a vial is in use, note the date of first entry. Benzyl alcohol limits\nmicrobial growth for a period; it does not do so indefinitely.",[11,142,144],{"id":143},"using-it","Using it",[16,146,147,148,152,153,157],{},"The arithmetic of reconstitution is mass divided by volume, and the\n",[46,149,151],{"href":150},"\u002Ftools\u002Freconstitution-calculator","reconstitution calculator"," works it in both\ndirections. The technique matters as much as the arithmetic: run the diluent down\nthe inside wall of the vial rather than directly onto the lyophilised cake, and\nswirl rather than shake. See\n",[46,154,156],{"href":155},"\u002Fresearch\u002Fpeptide-aggregation-and-handling","peptide aggregation and handling","\nfor why agitation is the specific thing to avoid.",[11,159,161],{"id":160},"what-we-supply","What we supply",[16,163,164],{},"Bacteriostatic water is supplied as a sterile solution with sterility and\nendotoxin specifications, not as an assayed peptide. It carries no purity figure\nand no peptide Certificate of Analysis, and we will not print one.",{"title":166,"searchDepth":167,"depth":167,"links":168},"",2,[169,170,171,172,173,174],{"id":13,"depth":167,"text":14},{"id":21,"depth":167,"text":22},{"id":53,"depth":167,"text":54},{"id":126,"depth":167,"text":127},{"id":143,"depth":167,"text":144},{"id":160,"depth":167,"text":161},null,"Solvents","md",[179,182,185],{"question":180,"answer":181},"Does bacteriostatic water have a purity percentage?","No, and any vendor quoting one is quoting a number that does not exist. It is a solvent, not an assayed peptide, so there is no HPLC purity figure and no peptide Certificate of Analysis. What it does have are sterility and endotoxin specifications, and those are the relevant quality controls for it.",{"question":183,"answer":184},"What is the difference between bacteriostatic and sterile water?","Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits microbial growth and allows a vial to be entered more than once. Sterile water contains no preservative and is single-use — once the stopper is pierced, any organism introduced can multiply freely.",{"question":186,"answer":187},"Why does benzyl alcohol matter for the peptide, not just the water?","Benzyl alcohol is a small amphiphilic molecule, and there is literature on preservatives of this kind promoting aggregation in some proteins and peptides. For most short research peptides it is unproblematic, but for aggregation-prone material it is one variable worth controlling — which is a reason to prepare working solutions in preservative-free diluent where the work allows it.",{},true,"\u002Fcompounds\u002Fbacteriostatic-water",[192,193],"10 mL vial","30 mL vial",90,[],[197,198],"peptide-aggregation-and-handling","endotoxin-and-sterility-testing",{"title":5,"description":166},"compounds\u002Fbacteriostatic-water","Sterile water containing 0.9% benzyl alcohol as a bacteriostatic agent, used as a diluent for reconstituting lyophilised peptides.","0VIYe6s0Z95lx92NZEVjaNkD_mqPXlDRFV1N3nWhULY",[],[205,208],{"path":48,"title":206,"description":207},"Endotoxin and Sterility Testing: The Analyses a Peptide COA Doesn't Cover","Purity and identity say nothing about bacterial endotoxin or sterility. What the LAL assay measures, why endotoxin survives sterilisation, and when these tests are relevant to in-vitro work.",{"path":155,"title":209,"description":210},"Why Peptide Solutions Go Cloudy: Aggregation and Handling","Shaking a reconstituted peptide is the most common way to ruin one. The interfacial mechanism behind aggregation, why lipidated peptides are worse, and the handling practice that follows from it.",1787473952836]