为加强医疗器械产品注册工作的监督和指导，进一步提高注册审查质量，国家食品药品监督管理总局组织制定了本产品注册技术审查指导原则。本指导原则旨在指导注册申请人对肌酸激酶测定试剂（盒）注册申报资料的准备及撰写，同时也为技术审评部门对注册申� 查看更多>

DNA甲基化是一种重要的表观遗传现象，在细胞分化、发育及增殖过程中起着十分重要的作用。近来研究发现，肿瘤细胞中基因组总体甲基化水平的降低和某些基因启动子区发生过甲基化是肿瘤最早，也是最常见的分子改变之一。异常DNA甲基化与肿瘤抑制基因的转录� 查看更多>

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MethodsfortheDetectionofD-Amino-AcidOxidaseRyuichiKonno1*1DepartmentofMicroBIOLOGy.DokkyoUniversitySchoolofMedicine,Mibu,Tochigi321-0293.Japan.*Towhomcorrespondenceshouldbeaddressed:RyuichiKonno,DepartmentofMicrobiology.DokkyoUniversitySchoolofMedicine,Mibu,Tochigi321-0293.Japan.Email:konno@dokkyomed.ac.jpBiol.Proced.Online1998;1:27-31.doi:10.1251/ 查看更多>

GlucosamineRapidAssayMRTHOD:Placesample(containing0.5-10µgGlcN)inaPyrexscrewcappedtube.AddHCltoafinalconcentrationof2Nandafinalvolumeof0.6ml.Flushwithnitrogen.Stoppertightlyandhydrolyze16hat100oC.Preparestandardscontaining0-20µgGlcNfromastocksolutionof1.5mg/ml.(Use0,3,5,8,10,12mlofstocksolutionandaddwatertomakeupto300µl.Thenadd300 查看更多>

EnzymeKineticsassayoftheWTToassay17b-HSDactivityinlysates,cellswereharvested48haftertransfectionusingPBSEnzymeFreeCellDissociationSolution(specialtyMediaInc.,Lavellette,NJ),frozenondryiceandstoredat-80C.Cellpelletswerethawedonice,resUSPendedin:*10mMTris-HCl(pH7.4)/150mMKCL/1mMEDTA/2mMDithiothreitol(DTT)atproteinconcentrationof3-6mg/ml,andsnap-froze 查看更多>

CellulaseassaysCellulaseenzymesshowactivityduringtheripeningofsomefruits,wheretheireffectsoncellwallsresultsinsofteningofthefruit.Incasesofprogrammedcelldeath,suchastheformationofaerenchyma(largeairspacesinthecortexofplantsinfloodedsoils),andintheabscissionzonesofleavesandfruits,cellulasesareonceagainveryactive,breakingdownthecellulosewallsofthedea 查看更多>

ProteaseassayIncertainfruits,suchaspineapplesandmangoes,thefleshcontainsprotein-digestingenzymes(proteases).Thesemayplayapartinhelpingtosoftenthefruittissuesasthefruitripens,makingitevenmoreattractivetoanimalsthatmightdispersetheseeds.Soperhapstheactivitiesoftheseproteasesenzymeswillincreaseduringtheripeningprocess.Applicationsofplantproteases,such 查看更多>

Polyphenoloxidase(catecholoxidases)assayBrowningofthecutsurfaceofsomefruitsandvegetablesisduethepresenceofagroupofenzymescalledpolyphenoloxidases.Theseenzymesarereleasedbythebrokencellsandtheycatalysethereactionbetweencolourlessmoleculescalledpolyphenolsandmolecularoxygen.Thisreactioncreatescolouredcompoundsandthesenewcompundscanspontaenouslycrossr 查看更多>

PolygalacturonaseassayThisenzymeisfamousforbeinginvolvedinthedevelopmentoftheGMOtomatoes(moreinformationfromthelinkatthefootofthispage).Thecellsofthesetomatoeshavebeengeneticallymodifiedtocontainareversedcopyofthegeneforthisenzyme.Thisproducesanti-sensemRNAwhichcombineswiththenormalmRNAforpolygalacturonase,effectivelysupressingitssynthesis.Asaresul 查看更多>

PectinaseassayPectinasesareactuallyamixtureofenzymes,which,alongwithotherssuchascellulase,arewidelyusedinthefruitjuiceindustrywheretheyarewidelyusedtohelpextract,clarifyandmodifyfruitjuices.(Seethefootofthispageformoreinformation)Pectinsarelargepolysaccharidemolecules,madeup(mainly)ofchainsofseveralhundredgalacturonicacidresidues.Enzymesinthispecti 查看更多>