The use of new staining techniques for human chromosome identification.

An accepted feature of technological develop- ment and its associated accumulation of data is that progress occurs in an irregular fashion with 'break throughs' being interspersed by periods of relative inactivity. In the halcyon years of 1955 to 1961, human cytogenetics experienced a revolution which brought the field within the scope of most genetic laboratories. The resulting increase in the volume of cytogenetical data being published has seen few parallels in the history of science. A review of the period The majority of contributions merely emphasized biological situa- tions known to exist and described in part previously. Over this period, the limitations in identifying human chromosomes on morphological criteria remained a major deficiency of the work and the IIIrd Chromosome Standardization Conference (Chicago Conference, 1966) summarized and de- fined those chromosomes which could be further specified by a combination of their morphological and autoradiographic patterns. Only those who have had cause to use autoradiography for chromo- some identification will appreciate the strictures im- posed by time, resolution, and sample size by this technique.