Cloning of lymphocytes from whole blood by limiting dilution

A simple whole blood limiting dilution technique was developed to clone human lymphocytes non-specifically. The geometric mean frequency of clone forming cells in 13 normal individuals was found to be 31.1%. Compared with measurement of proliferation in mass suspension culture, cloning provides a quantitative and easily interpretable endpoint for a variety of lymphocyte studies and its use in measurement of radiation sensitivity is presented as an example.