A simplified micro-method for cytotoxicity testing using a flat-type titration plate for the detection of H-2 antigens.

A new micro-method for cytotoxicity testing using a flat-type titration plate has been developed. This micro-method is so simple that it involves no washing and staining procedures. In this method, cell viability is judged on the basis of the refractility change in the lymphocytes seen under the phase-contrast microscope. This micro-method has higher sensitivity and reproducibility than the dye exclusion method and 51Cr-release assay. Fixation of cells with glutaraldehyde and tight covering of the plate allow us to read the result even after 3 weeks. These advantage of the new method enable us to deal with a large number of samples at one time. We also introduce a rapid technique for the preparation of a cell suspension from the lymph node without killing the animal.