Use of formalin-fixed melanoma cells for the detection of antibodies against surface antigens by a micro-immune adherence technique.

Established malanoma cell lines were fixed in suspension with 4% formalin and tested for antigenic activity against sera from melanoma patients in a micro-immune adherence test. By incubation of formalin-fixed cells in serum-free medium the unspecific background rosette formation was substantially reduced to below 10%. As could be demonstrated in absorption experiments with viable and formalin-fixed tumor cells, surface antigens reacting with sera from melanoma patients are largely unaffected by formalin treatment.