Observations on the technique for the study of human chromosomes by the culture of leukocytes from peripheral blood.

A critical analysis of the various features of blood leukocyte culture for the study of human chromosomes was carried out. The following observations were made: (1) Fasting blood was essential for effective separation of leukocytes. (2) These cells are easily obtained by differential centrifugation and RBC sedimentation. (3) Non-specific agglutination of leukocytes was prevented by the use of Eagle's medium for suspension cultures. (4) No contamination occurred in a series of 50 leukocyte cultures to which antibiotics were not added. (5) Addition of an experimental Phaseolus vulgaris extract at concentration of 1 x 10(-4) to cultures resulted in a 12 to 15% mitotic index. (6) Desacetyl-methyl-colchicine (Colcemid) had optimal effect at concentration of 0.1 mug./ml. (7) Distilled water added to cell suspension in culture medium (5: 1) was an effective hypotonic agent.A simplified technique of leukocyte culture for chromosome preparations is proposed.