Abstract
Established melanoma cell lines were fixed in suspension with 4 % form lin and tested for antigenic activity against sera from melanoma patient in a micro‐immune adherence test. By incubation of formalin‐fixed cell 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 unaffect by formalin treatment.