Immunoperoxidase staining on frozen tissue sections as a first screening assay in the preparation of monoclonal antibodies directed against small cell carcinoma of the lung.

To prepare monoclonal antibodies against small cell carcinoma of the lung (SCCL), we have used an SCCL-derived cell line as immunogen. A first screening of hybridoma supernatants was performed on frozen tissue sections of a biopsy with histologically proven SCCL involvement. Screening on tissue sections is a valuable technique, especially for the isolation of monoclonal antibodies directed against tumor antigens. A drawback of this procedure is that it is laborious. To circumvent this, we have reduced the number of supernatants to be screened by increasing the number of seeded hybridomas per well. Although this resulted in the growth of 5-20 hybridomas per well, among which there was always at least one that secreted antibodies against 'common antigens', clones that secreted specific antibodies could still be revealed by testing supernatants which were preabsorbed with thrombocytes. This has resulted in the isolation of 7 monoclonal antibodies directed against SCCL associated antigens.