1. A method for the separation of chromatin threads from the resting nucleus of leukemic cells has been described.
2. The isolation of the chromatin strands was accomplished by purely mechanical means, and the separation, including extraction and purification in the centrifuge, required only about 1 hour.
3. Evidence is presented to show that the chromatin strands are morphologically related to the chromosomes, if not identical.
4. It seems probable that, by the present technique, chromatin strands can be obtained from different mammalian tissues for direct microscopical examination and biochemical analysis.