A quantitative assessment by flow cytometry of the preservation of the Thy-1 antigen by various fixation procedures.

A quantitative assessment of the effects of various fixatives upon the preservation of the Thy-1 surface antigen has been undertaken. A panel of 5 monoclonal antibodies (MAbs) have been reacted with mouse lymphocytes treated with various fixatives, and their binding analysed by flow cytometry using a fluorescence activated cell sorter. It was found that 2% paraformaldehyde (PFA) provided the best antigenic preservation, as detected by both the anti Thy-1.1 and anti Thy-1.2 MAbs. The effectiveness of 2% PFA fixation is further demonstrated by the immunohistochemical identification of the Thy-1 antigen in sections of mouse cerebellar cortex.