A Direct Method for Chromosome, Studies of Human Bone Marrow

Abstract

The direct method for chromosome studies has certain advantages over the short term culture technic. In the modification of the original method, the following changes were made. Heparinized bone marrow specimens are used. This permits a 24 hour delay in processing when the specimen is refrigerated. Bone marrow buffy coat is used and the red cells are discarded. This eliminates contamination by the stroma of the red cells. A modified Carnoy''s fixative is used containing 2 parts of methanol to one part of glacial acetic acid instead of the usual 3:1 ratio. This enhances the demonstration of satellited chromosomes. Fixed material can be stored in the refrigerator at 4[degree]C for as long as 38 days or possibly longer. Giemsa strain was found to be superior to Orcein and Permount was preferred to Canada Balsam. The direct method lends itself readily to the facilities of routine and research laboratories. It is simple and reliable.