DNA:终结仿冒的利器

科技真的很神奇!脱 氧 核 糖核酸（DNA）竟然也可以用来防伪!这项由新加坡陆博生物科技（苏州）有限公司发明的技术被广泛应用于烟酒、制药、电子、印刷、芯片甚至书画艺术品的防伪用途。读者们一定很好奇，作为防伪标的的DNA是如何萃取、合成进而被用于这项世界上独一无二的防伪技术的呢？那么，就让我们先来认识一下DNA。     

DNA双螺旋模型没有确立分子生物学范式吗？——兼与颜青山先生商榷

本文在重新审视库恩的“范式”本意和DNA双螺旋模型发现的历史背景与科学价值基础上，提出了与颜青山先生截然相反的观点：DNA分子双螺旋模型是分子生物学范式的确立者。同时对颜文中有关分子生物学范式的方法纲领、逻辑基础和共同体心态的划分以及其他两个观点进行了商榷。     

Inhibition of DNA restrictive endonucleases and Taq DNA polymerase by trimalonic acid C60

Activities of trimalonic acid fullerene (TMA C_60) on DNA restrictive enzymatic reaction were investigated by using two restrictive endonucleases Hind III and EcoR I and plasmid pEGFP-N1 with single restric-tive site for both enzymes. Meanwhile, TMA C60 was also tested to clarify its effects on polymerase chain reaction (PCR) with the catalyst of Taq DNA polymerase and the template of plasmid pEGFP-N1. The products from restrictive reactions or PCR were detected by agarose gel electrophoresis. It was found that the product amounts from restrictive reactions or PCR decreased significantly with addition of TMA C60. The inhibition by TMA C60 was dose-dependent and IC50 values for reactions of Hind III, EcoR I and PCR were 16.3, 6.0 and 6.0 μmol/L, respectively. Addition of two scavengers of reactive oxygen species (ROS), L-ascorbic acid-2-phosphate ester magnesium and sodium azide at the con-centrations of 2―10 mmol/L did not antagonize the activities of TMA C60 against PCR and two restrictive reactions. However, increase of Taq DNA polymerase amounts in PCR system antagonized the activities of TMA C60. These data implied that TMA C60 was able to inhibit the activities of the three above-mentioned enzymes involved in DNA metabolism, and that this inhibition probably did not correlate to ROS.     

Direct electrochemical detection of PCR product based on charge transfer through DNA

Human genome project and genetic identification for inherited diseases will definitely have a profound impact on the diagnosis of diseases[1], which calls for rapid and accurate assays of DNA. Among different types of sensors, electrochemical DNA biosensors offer a promising alter-native means[2,3]. Recent efforts to elucidate the mecha-nism of charge transfer in DNA have demonstrated that the charge transfer is sensitive to the perturbation in base stack[4,5]. Long-range charge transfer i…     

Rapid Amplification of 5‘ cDNA End of S.Liaotungensis Choline Monooxygenase Using Inverse PCR RACE

Based on part of a known cDNA sequence of Suaeda Liaotungensis choline monooxygenase the author successfully cloned the 5‘ cDNA end of Suaeda Lianotungensis choline monooxygenase using Inverse PCR RACE with a specially designed 5‘-phosphated RT primer and two pairs of specific inverse PCR primers.Compared with the anchored PCR RACE,inverse PCR RACE has bettter specificity and higher amplification.     

古DNA技术：民族考古学研究的新视角

古DNA技术使考古学对古人遗骸的研究得以进入分子水平，为民族考古学对过去人群的研究，如性别与家系鉴定、族属分辨、群体内部关系及群体迁徒等，提供了直接的证据，为高新技术与人文学科的交叉研究开辟了全新的领域。     

崭露头角的PCR技术

1865年,美国第16任总统林肯遇刺身亡,时年才56岁。然而,一些研究人员声称,他即使不遇害,也将寿终正寝了。因为他已经患上了一种叫“马方综合症”的疾病,患此病的人大多数只能活到这个年纪。 当前,这种事后诊断的依据只能来自于对林肯DNA所进行的遗传分析。林肯死亡已100余年,漫长的岁月已使他的遗传试样变得很稀少,显然这种分析是相当困难的。但是现在科学家已经发明了一项新技术,它可对遗传试样进行几乎是无限的扩增和复制,从而有可能获得足够多的林肯遗传材料,来证实他们的猜测诊断。