水柱法场扩大提高CE-UV检测核酸灵敏度

目的：采用水柱法场扩大堆积技术,提高毛细管电泳紫外分析核酸灵敏度。方法：已知浓度的DNA Marker为标准样品,TE缓冲液递度稀释,压力进样前加一段去离子水柱（0.5psi,20s）,观察不同浓度下压力进样紫外检测图谱。结果：在对分离度无明显影响下,将压力进样时间延长至0.5psi,990s,与常规的压力进样（0.5psi,10s）相比,灵敏度提高了94.4倍。与时间延长后的压力进样（0.5psi,90s）相比,灵敏度提高8.2倍,最低检测总浓度为1ng/μl,DNA的检测限降至80ng/ml（S/N=3）,比前人报道的7ng/μl检测限提高了87.5倍。结论：验证了水柱法场扩大堆积注射可以有效提高毛细管电泳紫外检测核酸灵敏度。

Enhanced the CE-UV Detection Sensitivity of DNA by the Water-plug Field-amplified Stacking Injection

Objective: Enhancing the UV detection sensitivity of capillary electrophoresis for DNA by water-plug field-amplified stacking injection . Method: The known concentration of DNA marker were as standard samples, TE buffer diluted the standard samples gardiently, inserted a water-plug(0.5psi, 20s)before pressure injection, observed the CE-UV map in different concentration.Result: The pressure injection time was prolonged until 0.5psi, 990s without deteriorating the resolution, compared to normal pressure injection(0.5psi, 10s)and extended pressure injec-tion(0.5psi, 90s), the sensitivity was enhanced 94.4 folds and 8.2 folds respectively. 1ng/μl was the lowest detection overall concentration of DNA, 80ng/ml(S/N = 3)is the detection limit, the result was 87.5 folds better than the former researchers' detection limit of 7 ng/μl. Conclusion: The experiment validated the water-plug field-amplified stacking injection was an effective approach to enhance the CE-UV detection sensitivity of DNA.