激光显微捕获技术用于尿液脱落细胞DNA检测

目的采用激光显微捕获技术（LCM）捕获尿液脱落细胞,并进行STR分型。方法收集10份健康成人尿液样本,根据储存时间分组,其中新鲜尿液组（≤24h）分别采用Chelex-100及LCM联合DNA IQTM提取法提取DNA,储存尿液组（〉24h）再分为4℃组和室温组,分别在4～30d内不同时间点采用LCM联合DNA IQTM提取法提取DNA;各组提取的模板DNA进行扩增及SRT分型检验。结果新鲜尿液组采用LCM联合DNA IQTM提取法提取DNA,所有样本均可检出全部基因座（16个）,采用Chelex-100法则在部分基因座上出现等位基因丢失、非特异性扩增、峰值低等现象;4℃储存10d和室温储存4d以内的尿液经检验可明确判读12个以上基因座,4℃20～30d及室温7d,可检出7个以上基因座。结论 LCM技术可用于尿液检材的DNA分型检验,且检材应尽可能4℃保存并尽快检验。

Application of the laser capture microdissection technique in the urinary sediment DNA detection

Objective To assess the application value of laser capture microdissection(LCM) technique for isolating the urinary exfoliated cells from the urinary sediment.Methods 10 urine samples were collected from healthy adults,and then were divided into fresh urine group(≤24h) and stored urine group(>24h) according to storage time.For the fresh urine group,DNA was isolated using the Chelex-100 method and LCM combined DNA IQTM extraction method respectively.All samples of the stored group were further subdivided into two groups: 4℃-stored and room temperaturestored groups,and DNA was isolated using the LCM combined DNA IQTM extraction method at different time points from 4 to 30d.Finally,STR typing was carried out for all samples.Results With the LCM combined DNA IQ TM extraction method,all samples of the fresh urine group were genotyped successfully in all 16 STR loci.With the Chelex-100 method,however,drop-out,drop-in,low peak and other issues could be observed in some STR loci.More than 12 loci could be typed successfully for those samples which had been stored at 4℃ for 10 d or room temperature less than 4d,and more than 7 loci could be typed successfully for those samples which had been stored at 4℃ for 20~30d or room temperature for 7d.Conclusion The LCM technology can be used for DNA detection of urine samples,and the samples should be stored at 4℃ and analyzed as soon as possible.