Spurbeck J L, Zinsmeister A R, Meyer K J, Jalal S M
Division of Laboratory Genetics, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
Am J Med Genet. 1996 Feb 2;61(4):387-93. doi: 10.1002/(SICI)1096-8628(19960202)61:4<387::AID-AJMG15>3.0.CO;2-O.
Consistency of optimum chromosome spreading during harvest of cytogenetic specimens remains a major concern. We have tested the idea that a precise control of the drying rate (the time with which metaphase cells dry), as fixed cell suspension is placed on a slide or an in situ culture in last fixation, may be the answer. Amniocyte and lymphocyte cultures were allowed to dry at defined combinations of relative humidity (RH) and temperature (T) in a modified Thermotron environmental control unit. We were able to demonstrate, based on 2,250 amniocytes and 1,650 lymphocytes, that the metaphase area after drying was a function of RH and T for both in situ and non-in situ culture systems. As the RH and T increase, the metaphase area increases until a threshold is reached. Also, as RH increases, the slide drying time increases. Data obtained using a response surface regression, proportional hazards regression analysis and slide drying time studies are consistent with our model of chromosome spreading. Optimum metaphase areas can be achieved at various combinations of RH and T. We propose that the use of an environmental control unit is a practical way of achieving optimum chromosome spreading routinely and in a highly consistent manner.
在细胞遗传学标本采集过程中，实现最佳染色体铺展的一致性仍然是一个主要问题。我们测试了这样一种想法：当固定的细胞悬液置于载玻片上或在末次固定时进行原位培养时，精确控制干燥速率（中期细胞干燥所需的时间）可能是解决办法。在一个经过改良的Thermotron环境控制单元中，使羊水细胞和淋巴细胞培养物在特定的相对湿度（RH）和温度（T）组合下干燥。基于2250个羊水细胞和1650个淋巴细胞，我们能够证明，对于原位和非原位培养系统，干燥后的中期面积是RH和T的函数。随着RH和T的增加，中期面积增大，直至达到一个阈值。此外，随着RH的增加，载玻片干燥时间延长。使用响应面回归、比例风险回归分析和载玻片干燥时间研究所获得的数据与我们的染色体铺展模型一致。在RH和T的各种组合下都可以实现最佳中期面积。我们建议，使用环境控制单元是一种切实可行的方法，能够常规且高度一致地实现最佳染色体铺展。
