A simple but reliable technique has been developed for the mailing of plasma to chromosome laboratories for cytogenetic analysis. Cultures have been grown successfully from plasma which has been as long as four days in transit. Plasma is removed after heparinized whole blood has been left standing at room temperature for at least three hours. Phytohemagglutinin (0.1 ml. PHA/ml. plasma) and two to three drops of red cells are added to the plasma, and the specimen is immediately transmitted by air mail to the nearest cytogenetic laboratory. Sterile technique is used throughout.
