True Signal Loss After Autofluorescence Quenching (Tissue Imaging (Autofluorescence))

Question

Accepted Answer

Signal drops or disappears after applying Sudan Black B or other quenching treatments. Target staining reduced along with background. Tissue morphology may be affected. Common causes: 1) Excessive Sudan Black B concentration or incubation time 2) Use of organic mounting media causing SBB leaching 3) Overly aggressive sodium borohydride treatment reducing fluorophore signal 4) Quencher affecting antibody binding or fluorophore stability 5) Tissue damage from harsh chemical treatment Solutions: 1) Lower Sudan Black B concentration (start at 0.05%) or reduce incubation time 2) Ensure use of aqueous mounting media (SBB is alcohol-soluble) 3) Test cupric sulfate as gentler alternative to SBB 4) Use sodium borohydride conservatively and only when glycine/Tris insufficient 5) Always verify quenching did not erase true target signal using positive controls 6) Test on expendable sections first before applying to valuable samples