Age-Related Lipofuscin Accumulation (Tissue Imaging (Autofluorescence))

Question

Accepted Answer

Exceptionally broad excitation and emission spectra affecting multiple channels in aged tissues such as brain, heart, skeletal muscle, and retina. Age-dependent lysosomal pigment cannot be confined to single channel. Common causes: 1) Age-dependent accumulation of lipofuscin in lysosomes 2) Broad, overlapping excitation and emission spectra 3) Particularly prominent in metabolically active tissues 4) Increased accumulation in aged specimens Solutions: 1) Apply Sudan Black B (0.05-0.3% w/v in 70% EtOH for ~10 min) as primary quencher 2) Rinse thoroughly and mount in aqueous medium (SBB is alcohol-soluble) 3) Assign dim targets exclusively to far-red channels 4) Document autofluorescence baseline with no-primary controls in each channel 5) Consider spectral unmixing for mathematical separation of autofluorescence