[AgNORs (Ag nucleolar organizer regions)].

A quick and quantitative evaluation technique, "AgNORs-FCM", was developed to analyze Nucleolar Organizer Regions (NORs) stained with silver impregnation followed by cytofluorometric analysis. Cell suspension is stained with AgNORs similarly as described elsewhere for tissue sections, but with a modification of using a much lower concentration of silver nitrate. Cytological general rules in AgNORs-FCM are: 1) Specific exaggeration of side scatters (90 LSs) can be detected according to the intensity of AgNORs staining. 2) Significantly brighter 90 LSs were observed when cultured leukemia cell-line was applied to AgNORs-FCM. 3) AgNORs-FCM provides more specifically brighter 90 LS for cells in G2M and S phase, when gated along the P.I.-fluorescence. AgNORs-FCM can be applied to analyze clinico-pathological samples including neoplastic tissues, more quickly and quantitatively, than regular tissue staining with AgNORs.