George Terganian, Ph.D. 



CYTOGENETIC ANALYSISt 



The past decade has been a most decisive period for the advancement of experi- 

 mental mammalian cytology. Progress today appears even more exaggerated when 

 compared to a relatively stagnant period of some twenty-five years, resulting from 

 negative experiences and faltering views, due primarily to limited technical facilities. 

 Just how did this present surge of interest come about ? Until 1 950, the number of 

 cytologists familiar with mammalian chromosomes was very limited and included a 

 few who were equally active in plant cytology. The latter group of investigators 

 reviewed animal tissues periodically to reinstate the awareness of difficulties ascribed 

 to mammalian chromosomes by earlier workers. However, as time went on, more 

 favorable pretreatments and sources of tissue became available and the cumulative 

 results were most encouraging to the small but interested group of participants. A 

 number of independent reevaluations were conducted with the squash technique, 

 employing seminiferous tubules for meiotic bivalents, 1175 somatic chromosomes in 



f Thanks are extended to M. Bender, J. J. Clausen, K. Fredga, T. S. Hauschka, D. 

 Hungerford, R. Kato, I. Kline, U. Ising, G.J. Marshall, S. Makino, P. Moorhead, S. Ohno, 

 C. G. Palmer, M. Sasaki, and J. T. Syverton for their cooperation and help in extending the 

 coverage of this treatise to a broad variety of methods. The author wishes also to express 

 his gratitude to Dr. Sidney Farber and other members of the staff of The Children's Cancer 

 Research Foundation, for advice and recommendations and particularly for the facilities 

 provided that made these investigations possible. 



The investigations conducted at The Children's Cancer Research Foundation have 

 been supported in part by grants from the National Science Foundation (G9602), the 

 Damon Runyon Memorial Fund for Cancer Research (DRG-293), Research Grant A-4468 

 from the Institute of Arthritis and Metabolic Diseases, and from the National Cancer 

 Institute, USPHS No. CY3335. 



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