A photometric study of the standard Philadelphia (Ph1) translocation of chronic myeloid leukemia (CML).

A newly developed form of high resolution microscope photometry has been employed in a study of the relationships between the chromosomes involved in the standard Philadelphia (Ph1) translocation of chronic myeloid leukemia (CML). The intention of the investigation was to provide quantitative data on the relative amount of material exchanged between the No. 9 and No. 22 chromosomes. A marked consistency in the amount of material lost from the Ph1 was observed, and the balanced nature of the standard Ph1 translocation was confirmed. The data are also in accordance with the concept of a reciprocal exchange between the No. 9 and No. 22 chromosomes.