Imaging of In Situ Interferon Gamma Production in the Mouse Spleen following Listeria monocytogenes Infection

severe

Red Blood Cell and Heme-Related Autofluorescence

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.

💡 4 · ✓ 5

moderate

Fixation-Induced Aldehyde Fluorescence

Strong blue-green autofluorescence haze in formalin or glutaraldehyde-fixed tissues. Background increases with fixation duration and disproportionately contaminates lower-wavelength channels. Amplified by paraffin embedding and overfixation.

💡 5 · ✓ 6

moderate

Metabolic Cofactor Autofluorescence

Endogenous fluorescence from NADH, FAD, and other metabolic cofactors in high-metabolism tissues such as kidney, liver, pancreas, and spleen. Complex extracellular matrices contribute additional background.

💡 4 · ✓ 5