Double Fixation with Paraformaldehyde and Acetone for Optimal Immunocytochemical Demonstration of DNA Polymerase α

Abstract

Because the fixation procedure is a crucial step for immunocytochemical staining of DNA polymerase α, we sought an optimal fixation for demonstration of the enzyme using HeLa S3 cells. Double fixtion with paraformaldehyde and acetone produced intense stainability when slides were dipped in a 4% paraformaldehyde solution for 10 min, then in acetone for 5 rnin at 4°C. In contrast, fixation with ethanol or methanol resulted in considerable reduction of immunoreactivity. Single fixation with paraformaldehyde or acetone yielded intermediate stainability. Poor stainability also resulted in decrease of positive cells. (The J Histotechnol 12:285, 1989)