Red Blood Cell and Heme-Related Autofluorescence (Tissue Imaging (Autofluorescence))

Question

Accepted Answer

Strong autofluorescence across multiple channels in blood-rich tissues such as spleen, liver, brain, bone marrow, and vascularized tumors. Heme and porphyrins dominate signal especially when tissue is not thoroughly perfused. Common causes: 1) Residual red blood cells containing heme and porphyrins 2) Insufficient perfusion prior to fixation 3) High tissue vascularity 4) Blood clotting during perfusion Solutions: 1) Perfuse with PBS prior to fixation when possible 2) Include approximately 10 U/mL heparin in perfusion solution to reduce clotting 3) For human/postmortem or non-perfused tissues, wash sections longer 4) Consider pigment quenchers such as Sudan Black B or cupric sulfate 5) Assign low-abundance targets to far-red channels where RBC background is lower