用“咖啡环”法估测DNA含量

目的探讨DNA-溴化乙锭形成的"咖啡环"用于DNA含量的测定。方法将DNA与溴化乙锭混合,滴加在载玻片等载体上,蒸发后用凝胶成像系统观察、拍照,分析DNA的成环条件、环荧光强度与DNA浓度的相关性,以及"咖啡环"法评价DNA的灵敏度、适用范围等。结果 DNA-溴化乙锭溶液在载玻片、透明聚苯乙烯板等载体表面蒸发后可形成荧光环。在玻片上2μL点样时,DNA检出限可达到2ng/μL。在2ng/μL~1000ng/μL范围内,DNA浓度与环积分光密度拟合Logistic方程(R2=0.999)。结论 "咖啡环"法简单、快速,设备要求低,可用于DNA含量的高效、快速测定。

The method to estimate DNA concentration by "coffee ring" pattern

Objective To explore the feasibility of "coffee ring" effect in DNA high-throughput evaluation. Methods we mixed uniformly DNA solution and EB solution, then dripped different size of droplets on 5 kinds of substrates. After evaporation, the coffee ring was observed and photographed with LG2020 gel imaging analysis system. Analyzed the correlation among ring formation conditions,ring fluorescence intensity and DNA concentration, and looked for the sensitivity and applicable range of the method. Result DNA - EB solution can form fluorescent ring after surface evaporation on the slide, transparent polystyrene plate carrier and so on. The DNA detection limit can be up to 2ng/μl. DNA concentration and loop integral optical density fitting Logistic equation(R2=0,999) within 2ng/μl~1000ng/μl. Conclusion The coffee ring method is simple, fast and low equipment requirement,which can be used for high-throughput evaluation of DNA solution.