Observations on the use of diazo-1-H-tetrazole and phenylglyoxal in protein histochemistry as applied to human gingiva

A solution of diazo-1-H-tetrazole, freshly prepared by the diazotization of 5-amino-1-H-tetrazole under conditions to avoid explosion, was adjusted to pH 8.8, diluted (1∶1 or 1∶9) with 0.67 M bicarbonate buffer, pH 8.8, and used immediately as a histochemical reagent for demonstrating histidine, tryptophan, and tyrosine residues in deparaffinized sections… (More)