Detection of Apoptotic Cells in a Dexamethasone-Induced Thymic Apoptosis Model in Rats Using A Modified Warthin-Starry Silver Impregnation Method to Prevent Fading

Abstract

A modified Warthin-Starry (mWS) method was developed to stain apoptotic cells in tissue sections. Essentially the classical WS method is applied except for a minor change to prevent fading. In order to clarify the relationship between mWS-positive cells and apoptosis, apoptotic thymic tissues were examined on the rats treated with dexamethasone. The results clearly showed the distribution of mWS-positive cells to coincide well with that for apoptotic cells observed by terminal deoxynucleotidyl transferase (TdT)-mediated d-UTP-biotin nick end labeling (TUNEL) method. An additional characteristic is that nuclei of mitotic thymocytes, with highly condensed chromatin, are always stained. These observations suggest that the mWS method might be useful and convenient to detect condensed chromatin during apoptosis.