Triple immunohistochemical staining for bromodeoxyuridine and catecholamine biosynthetic enzymes using microwave antigen retrieval.

A method was developed for detection of bromodeoxyuridine (BrdU) in conjunction with other antigens in formalin-fixed paraffin sections with microwave antigen retrieval. The method was applied to rat adrenal medulla to demonstrate S-phase nuclei in epinephrine-producing cells stained for immunoreactive phenylethanolamine-N-methyltransferase and in norepinephrine-producing cells stained for immunoreactive tyrosine hydroxylase. The quality of staining for all three antigens was comparable to or better than that previously obtained with other techniques. This method provides an efficient tool for studying turnover of subpopulations of adrenal chromaffin cells. It should also be widely applicable to other cells and tissues.