描述

TheThermoScientificPierceBCAProteinAssayKitisatwo-component,high-precision,detergent-compatIBLeassayreagentsettomeasure(A562nm)totalproteinconcentrationcomparedtoaproteinstandard.

FeaturesoftheBCAProteinAssayKit:

• Colorimetric—estimatevisuallyormeasurewithastandardspectrophotometerorplatereader(562nm)
• Excellentuniformity—exhibitslessprotein-to-proteinvariationthandye-bindingmethods
• Compatible—unaffectedbytypicalconcentrationsofmostionicandnonionicdetergents
• Moderatelyfast—mucheasierandfourtimesfasterthantheclassicalLowrymethod
• Highlinearity—linearworkingrangeforBSAequals20to2000µg/mL
• Sensitive—detectdownto5µg/mLwiththeenhancedprotocol

Usedinmorelabsthananyotherdetergent-compatibleproteinassay,PierceBCAReagentsprovideaccuratedeterminationofproteinconcentrationwithmostsampletypesencounteredinproteinresearch.ThePierceBCAAssaycanbeusedtoassessyieldsinwholecelllysatesandaffinity-columnfractions,aswellastomonitorproteincontaminationinindustrialapplications.Comparedtomostdye-bindingmethods,theBCAAssayisaffectedmuchlessbyproteincompositionaldifferences,providinggreaterprotein-to-proteinuniformity.

Applications:
•Studyingprotein:proteininteractions
•Measuringcolumnfractionsafteraffinitychromatography
•Estimatingpercentrecoveryofmembraneproteinsfromcellextracts
•High-throughputscreeningoffusionproteins

HowtheBCAProteinAssayDetectsProtein:
TheBCAProteinAssaycombinesthewell-knownreductionofCu2+ toCu1+ byproteininanalkalinemediumwiththehighlysensitiveandselectivecolorimetricdetectionofthecuprouscation(Cu1+)bybicinchoninicacid.Thefirststepisthechelationofcopperwithproteininanalkalineenvironmenttoformalightbluecomplex.Inthisreaction,knownasthebiuretreaction,peptidescontainingthreeormoreaminoacidresiduesformacoloredchelatecomplexwithcupricionsinanalkalineenvironmentcontainingsodiumpotassiumtartrate.

Inthesecondstepofthecolordevelopmentreaction,bicinchoninicacid(BCA)reactswiththereduced(cuprous)cationthatwasformedinstepone.Theintensepurple-coloredreactionproductresultsfromthechelationoftwomoleculesofBCAwithonecuprousion.TheBCA/coppercomplexiswater-solubleandexhibitsastronglinearabsorbanceat562nmwithincreasingproteinconcentrations.TheBCAreagentisapproximately100timesmoresensitive(lowerlimitofdetection)thanthepalebluecolorofthefirstreaction.

ThereactionthatleadstoBCAcolorformationisstronglyinfluencedbyfouraminoacidresidues(cysteineorcystine,tyrosine,andtryptophan)intheaminoacidsequenceoftheprotein.However,unliketheCoomassiedye-bindingmethods,theuniversalpeptidebackbonealsocontributestocolorformation,helpingtominimizevariABIlitycausedbyproteincompositionaldifferences.

Pierce的Slide-A-Lyzer G2透析盒为样品透析提供了方便，灵活和高性能。这些第二代（G2）Slide-A-Lyzer透析盒是独立式，自浮式且可移液管装载的。使用连接到注射器的血清移液管或皮下注射针头（可选）可轻松完成样品的装载和取出（图1）。内置的气室可在透析过程中提供样品的浮力和盒子的垂直方向。Slide-A-Lyzer G2透析盒有5种容量，分子量截留值（MWCO）为2K，3.5K，7K，10K和20K。为实验选择合适的Slide-A-Lyzer G2卡带  音量范围 截留分子量0.25–0.5毫升1–3毫升5–15毫升10–30毫升25–70毫升2K货号 87717货号 87718货号 87719货号 87720货号 877213.5K货号87722货号87723货号87724货号87725货号877267K货号87727货号87728无法使用无法使用无法使用10K货号87729货号87730货号87731货号87732货号8773310K（伽玛射线照射）货号88250货号88251货号88252货号88253货号8825420K货号87734货号87735货号87736货号87737货号87738