The present invention relates to systems and methods for tissue processing and imaging including a counterintuitive inverse relationship between protein dye concentration and tissue sample protein content. Varying dye concentration in such a manner affords higher quality fluorescent imaging at depth in tissue when using optical sectioning microscopy or second harmonic generation (SHG) analysis. Methods of the invention thereby provide more usable histopathology images while reducing waste and reagent costs and are of particular utility in combination assays that include simultaneous protein and nuclear staining and SHG analysis.