实验技术相关名词.docx

《实验技术相关名词.docx》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、1.Fluorescence-activatedcellsorting(FACS)Fluorescence-activatedcellsorting(FACS)isaspecializedtypeofflowcytometry.Itprovidesamethodforsortingaheterogeneousmixtureofbiologicalcellsintotwoormorecontainers,onecellatatime,baseduponthespecificlightscatteringandfluorescentcharacteristicsofeachcell.Itisaus

2、efulscientificinstrumentasitprovidesfast,objectiveandquantitativerecordingoffluorescentsignalsfromindividualcellsaswellasphysicalseparationofcellsofparticularinterest.ThetechniquewasexpandedbyLenHerzenberg,whowasresponsibleforcoiningthetermFACS.[22]HerzenbergwontheKyotoPrizein2006forhisseminalworkin

3、flowcytometry.Thecellsuspensionisentrainedinthecenterofanarrow,rapidlyflowingstreamofliquid.Theflowisarrangedsothatthereisalargeseparationbetweencellsrelativetotheirdiameter.Avibratingmechanismcausesthestreamofcellstobreakintoindividualdroplets.Thesystemisadjustedsothatthereisalowprobabilityofmoreth

4、anonecellperdroplet.Justbeforethestreambreaksintodroplets,theflowpassesthroughafluorescencemeasuringstationwherethefluorescentcharacterofinterestofeachcellismeasured.Anelectricalchargingringisplacedjustatthepointwherethestreambreaksintodroplets.Achargeisplacedontheringbasedontheimmediatelypriorfluor

5、escenceintensitymeasurement,andtheoppositechargeistrappedonthedropletasitbreaksfromthestream.Thechargeddropletsthenfallthroughanelectrostaticdeflectionsystemthatdivertsdropletsintocontainersbasedupontheircharge.Insomesystems,thechargeisapplieddirectlytothestream,andthedropletbreakingoffretainscharge

6、ofthesamesignasthestream.Thestreamisthenreturnedtoneutralafterthedropletbreaksoff.TheacronymFACSistrademarkedandownedbyBecton,DickinsonandCompany.[23]Amongthelargemajorityofresearcherswhousethistechnologyforsortingoranalysis,thistermhasbecomegenericized,muchlikeXeroxforphotocopyorKleenexforfacialtis

7、sue.2.TUNELassayTerminaldeoxynucleotidyltransferasedUTPnickendlabeling(TUNEL)isamethodfordetectingDNAfragmentationbylabelingtheterminalendofnucleicacidsMethodTUNELisacommonmethodfordetectingDNAfragmen