Isolation of deoxyribonucleic acid from Mycobacterium avium by rapid nitrogen decompression.

Deoxyribonucleic acid (DNA) of high molecular weight could be isolated from cells of Mycobacterium avium if the cells were exposed to nitrogen gas at 1,500 lb/in2 for 30 min and then brought to atmospheric pressure by rapid decompression. DNA isolated from the cells had a molecular weight of 4.8 x 10(6) to 17.4 x 10(6). DNA was also released into the fluid in which the cells were suspended during nitrogen decompression. One-half of this DNA, representing 3% of the total DNA phosphorus in the cells had a uniform molecular weight of 4.2 x 10(6). This DNA was linear in conformation, and removal of associated carbohydrates did not change its sedimentation rate. The biological function or significance of the 4-megadalton DNA was not determined.