ApplicationNotes | Immunohistochemistry:5-10μg/mL(Seebelowprotocol.)
Optimalworkingdilutionsmustbedeterminedbyenduser.
ImmunohistochemistryProtocolforAnti-Neurofilament200kD
Idealspecimensareobtainedfromfrozensectionsfromshock-frozentissuesamples.Thefrozensectionsaredriedintheairandthenfixedwithacetoneat-15to-25°Cfor10min.Excessacetoneisallowedtoevaporateat15-25°C.Materialfixedinalcoholandembeddedinparaffincanalsobeused,see(Altmannsbergeretal.,1982).Theantibodyappearstoreactwithtissuefixedinformaldehydeforashorttime(10min)(Debusetal.,1983).Otherfixationconditionsmustbefirsttestedbytheinvestigator.
Itisadvantageoustoblockunspecificbindingsitesbyoverlayingthesectionswithfetalcalfserumfor20-30minat15-25°C.Excessoffetalcalfserumisremovedbydecantingbeforeapplicationoftheantibodysolution.Cytocentrifugepreparationsofsinglecellsorcellsmearsarealsofixedinacetone.Thesepreparationsshould,however,notbedriedintheair.Instead,theexcessacetoneisremovedbybrieflywashinginphosphate-bufferedsaline(PBS).
Furthertreatmentisthenasfollows:
Overlaythepreparationwith10-20μLantibodysolutionandincubateinahumidchamberat37°Cfor1h.
DiptheslidebrieflyinPBSandthenwash3timesinPBSfor3min(usefreshPBSeachtime)
Wipethemarginsofthepreparationdryandoverlaythepreparationwith10-20μLofananti-mouseIg-FITCoranti-mouseIg-PODantibodyandallowtoincubatefor1hat37°Cinahumidchamber.
Washtheslideasdescribedabove.
Thepreparationmustnotbeallowedtodryoutduringanyofthesteps.
Ifusinganindirectimmunofluorescencetechnique,thepreparationshouldbeoverlaidwithasuitableembeddingmedium(e.g.Moviol,Hoechst)andexaminedunderthefluorescencemicroscope.IfaPOD-conjugatehasbeenusedasthesecondaryantibody,thepreparationshouldbeoverlaidwithasubstratesolution(seebelow)andincubatedat15-25°CuntilaclearlyvisIBLered-browncolordevelops.Anegativecontrol(e.g.onlythesecondaryantibody)shouldremainunchangedincolorduringthisincubationperiod.Subsequently,thesubstrateiswashedoffwithPBSandthepreparationisstained,ifdesired,withhemalumstainforabout1min.ThehemalumsolutioniswashedoffwithPBS,thepreparationisembeddedandexamined.
Substratesolutions:
Aminoethyl-carbazole:
Dissolve2mg3-amino-9-ethylcarbazolewith1.2mLdimethylsulfoxideandadd28.8mL0.05MTris-HCl,pH7.3,and20μL3%H2O2(w/v).Preparesolutionfreshlyeachday.
Diaminobenzidine:
Dissolve25mg3,3"-diaminobenzidinewith50mL0.05MTris-HCl,pH7.3,andadd40μL3%H2O2(w/v).Preparesolutionfreshlyeachday. |