目的 调查样品中常见成份对"咖啡环"法DNA检测的影响. 方法 将含有不同浓度SDS、NaCl等的DNA-EB滴加到载玻片上,室温自然蒸发,用凝胶成像系统观察荧光沉积形貌(Deposition Pattern,DP)、计算积分光密度(Integrated Optical Density,IOD),分析量效关系. 结果 低浓度非DNA成份存在时, DP仍以环状沉积为主,但有年轮环、放射纹等成份特异性细微差异.浓度高时, DP因成份而异,可为环+散在光点型(NaCl)、中央光斑+弱小环型(SDS)、同心或年轮状多环型(TritonX-100)、环+斑点型(H+)等.非DNA成份对DNA含量估计有不同程度影响,但估计值多数在0.5~2倍以内.结论 样品成份对DNA的DP和IOD均有影响,但不影响DNA含量的粗略估计,且能提供样品纯度和残留物信息.%Objective To investigate the influences of drop components on the"coffee ring" test of DNA. Methods The DNA-EB drops containing SDS, NaCl, etc, were evaporated on glass slides. After evaporation, the fluorescent Deposition Pattern (DP) and Integrated Optical Density (IOD) was acquired with a gel imaging system. The dose-effect relationship was analyzed. Result When the non-DNA components concentration is low, the DP was still characteristiced by peripheral rings, subtle component-specific differences, such as tree-ring like structure and radial crack, existed. At high concentrations, DP was various, which may be ring + scattered dots (NaCl), central spot + small weak ring (SDS), concentric/tree-ring (TritonX-100) or ring + spot (H+), et al. Non-DNA components had little effect on IOD(0.5~2 times). Conclusion Non-DNA components in DNA-EB drops influences both the DP and IOD, but rough estimation of DNA concentrations is still effective. Moreover, analyzing the DP can provide more informations about sample purity and residue.
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