A method to study in vitro proliferation of lymphocytes from individual mice on repeated occasions.

Overview

A micro-method was developed that allowed the proliferation of blood lymphocytes from individual mice incubated with phytohemagglutinin to be measured on repeated occasions. Lymphocytes were isolated from 0.4 ml of heparinized blood by centrifugation through a Ficoll-Hypaque solution. This amount of blood could be taken repeatedly from individual mice and yielded 4-8 X 10(5) lymphocytes. Fifty thousand lymphocytes were incubated with 0.2 ml of medium RPMI 1640 containing 5% human serum in round bottom micro-titer wells. Using this technique lymphocytes from individual mice of the same strain were shown to differ consistently in their responses to PHA.