2021-07-29【原创】荧光微球吞噬实验的Protocol

最近有两位战友发信询问我的荧光微球吞噬实验的Protocol。

现分享于此：

LatexBeadsPhagocytosisassay

---Materials

*Fluorescencelabeledlatexbeads(1umdiameter),2.5%aqueoussUSPension
*3%BSAcontaining25mMNa2HPO4,pH6.0
*0,3%(w/v)azide
*Culturemediumcontaining5%FBS
*Distilledwater,PBS
*Bathsonication,6(12)-wellplates

---Cellcultureandtreatment

1,Inoculateplateswith7,0104cells/cm2perwell.Incubateat37℃,5%CO2for24hr,bestuntil50-70%confluenceisreached

2,Removeculturemediumandexposethecellstotestmaterial.Incubateat37℃,5%CO2for24hr.

---Preparationofcoatedlatexbeads

1，Washlatexbeadswithdistilledwaterandpelletat10,000gfor8minatRT.

2，Resuspendlatexbeadsin3%BSAcontaining25mMNa3PO4(pH6.0)andincubateatRTfor15minwithbathsonication.
*CoatingbeadsinBSAinsuresbeadsremaininamonodispersestate.

3，Washthebeadsoncewithculturemediumcontaining5%FBS.

4，Resuspendthebeadsinculturemediumatconcentration2.0%.Thisisbeadsstock.Storedindarknessat4℃.

---Assay

1，Controlsandsamples:Intactcontrol(Nostaining)1well
-Negativecontrol(azidetreated)1well
-Normalcontrol1well
-sample5wells

*Inordertodifferentiatebetweenphagocytosedbeadsandbeadsnonspecificallyadheretothecellsurface,controlcellsareexposedto0,3%(w/v)azidefor10minpriortotheadditionofcoatedbeads.Thistreatmentcompromisesmicroglialenergeticprocessesandfewbeadswereinternalizedasobservedbyfluorescentmicroscopy.Meanfluorescenceofazide-treatedmicrogliawasusedasthenegativecontrolandwassubtractedfromvaluesobtainedinexperimentalsamples.

2，Forexperimentsusing6well-plates,15μlbeadsstockin1mlculturemediumisappliedtoeachwell.Votexthebeadsstockwellandtakeout105μlandaddinto7mlculturemedium.Bathsonificatefor10minatRTindarkness.Thisisbeadsworkingsolution.

Forexperimentsusing12well-plates,6μlbeadsstockin0.4mlculturemediumisappliedtoeachwell.

3，WasheachwelltwicewithPBSandreplacewithbeadsworkingsolution,1ml/wellfor6-wellplate,0.4ml/wellfor12well-plate.Incubateinthedarkat37℃for80-120min.

4，Removebeadsworkingsolutionandwash3timeswithPBStoremoveexcessbeads.

5，LiftthecellsbyscrappingortrypsinizationandwashthecellswishPBS.

6，StainwithPI(4ug/mlfinalconcentration)andrunforFACS.