No abstract

Tissue autofluorescence frequently hampers visualization of immunofluorescent markers in formalin‐fixed paraffin‐embedded respiratory tissues. We assessed nine treatments reported to have efficacy in reducing autofluorescence in other tissue types. The three most efficacious were eriochrome black T, Sudan black B and sodium borohydride. We then further characterized these changes in autofluorescence using white light laser confocal multi‐lambda analysis. Additionally, we assessed the impact of steam antigen retrieval and serum application on human tracheal tissue autofluorescence. Functionally fitting this multi‐lambda data to 2‐dimensional Gaussian surfaces revealed that steam antigen retrieval and serum application contribute minimally to autofluorescence and that the three treatments are disparately efficacious. Together these studies provide a set of guidelines for diminishing autofluorescence in formalin‐fixed paraffin‐embedded human respiratory tissue. Additionally, the characterization techniques are transferable to similar questions in other tissue types as demonstrated on frozen human liver tissue and paraffin embedded mouse lung fixed in different fixatives.