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1.加入solution.III，经10分钟离心后细菌沉淀怎么不结实，有的漂浮在液面，有的贴在离心管壁上，一摇晃即破碎脱落下来？细菌的用量太少，导致产生的沉淀主要是盐分的沉淀，因为缺少变性的细菌蛋白和细菌基因组DNA 的缠绕，沉淀就显得不结实。解决方法：将细菌的用量增加。 2.加入soln.III，经10分钟离心后细菌沉淀怎么不结实，呈大块的水泡状，上清较少？（1）使用了过多的细菌，导 ...

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DNA 限制性内切酶消化是基因分析中的关键步骤。内切酶是最关键的工具酶。限制性内切酶是一类具有严格识别位点，并在识别位点内或附近切割双链 DNA 的脱氧核糖核酸酶。 酶单位规定为：在最适反应条件下 1 小时完全消化 lμg λDNA 的酶量为 1 个单位。需注意酶单位数是以切割线性 DNA 为标准定出的。消化其它种 DNA 则应根据 DNA 分子大小、形状适当增加或减少所需 ...

焦锋，楼程富 （浙江大学蚕学系，杭州310029） 摘要：综述了RAPD技术的一些理论性问题，包括RAPD与其它分子标记技术相比的优点，影响结果重复性的因素，显性标记产生的原因，条带取舍的标准等。提出在实验中解决这些问题的一些方法：严格控制反应条件，采用单倍体和单剂量标记，系统学研究中要结合其它方法进行分析，定位基因时要选用合适的群体等。 1.RAPD技术原理及特点 1．1原理RAPD（Rando ...

DNeasy® 96 Plant Protocol for Isolation of DNA from Fresh Plant Leaves Using the Mixer Mill MM 300 一、Important notes before starting （使用前的重要注释） 1、Take time to familiarize yourself with the Mixer ...

一．概述：基因敲除是自80年代末以来发展起来的一种新型分子生物学技术，是通过一定的途径使机体特定的基因失活或缺失的技术。通常意义上的基因敲除主要是应用DNA 同源重组原理，用设计的同源片段替代靶基因片段，从而达到基因敲除的目的。随着基因敲除技术的发展，除了同源重组外，新的原理和技术也逐渐被应用，比较成功的有基因的插入突变和iRNA ，它们同样可以达到基因敲除的目的。二．实现基因敲除的多种原理和方法 ...

Isolation of Mouse genomic DNA 1.Kill mouse by cervical luxation and dissect liver.Add to a 50ml tube and place on liquid nitrogen.Grind to a powder under liquid nitrogen using a mortar and pestle. 2. ...

1.Excise band of interest from a TAE gel; estimate volume by weighing the gel slice. 2.Dissolve the gel slice in 3 volumes of NaI (from Geneclean kit)at 55E C for 5 min or until the gel dissolves. 3.A ...

本法用含EDTA的溶液洗涤细胞，SDS（十二烷基硫酸钠）破碎、裂解细胞，消化蛋白质，使核蛋白解聚并使细胞内的DNA酶失活，用酚、氯仿变性蛋白质并去除杂质，最后用乙醇沉淀得到纯化的DNA。 1.裂解缓冲液 2.苯酚-氯仿溶液 3.氯仿-异戊醇溶液 4.冰无水乙醇及70%乙醇 5.TE缓冲液 6.5mol/L NaCl 1.处死小白鼠一只，取新鲜肝脏，用生理盐水清洗去血水。 2. ...

Important : Extract the DNA within one week of receiving samples.Samples that have been processed should be frozen to prevent degradation.Freeze samples between use each day. 1.Add 600 ml of 50 mM NaO ...

John Mundy Institute of Molecular BiologyCopenhagenDenmark http://www.arabidopsis.org/info/Protocols_Mundy2.jsp#Footprint 1)probe: same as used for gelshift)isolated by isotacelectrophoresis w/out E ...

1.Obtain 65-100 µl of blood by retro-orbital bleed with a heparinized microcapillary tube.Expel blood immediately into a 1.5 ml microfuge tube containing 20 µl of 10 mM EDTA.Mix immediatel ...

This is a brief overview of how a Southern blot (more formally called an DNA blot)is performed and what type of data you can obtain form one. Figure 1.Southern blots allow investigators to determine ...

1.Prepare or obtain Buffered phenolpH 8.Add 2 crystals of 8-Hydroxyquinoline to prevent oxidation.This also identifies the organic phase as yellow-colored. 2.Combine DNA sample with an equal volume of ...

1.Separate DNA fragments in an agarose gel cast with 0.5 mg/ml Ethidium bromide.Locate bands with a hand-held long-wave UV lamp. 2.Slice the gel with a razor blade above and below the bands of interes ...

i want to know how can i extract DNA from water microbe? -tanklm- -------------------------------------------------------------------------------- Standard DNA extraction proceedures should work fine ...

实验步骤： 1、Inoculate from an overnight grown in LB.从培养过夜的LB平板上挑取单菌落 。 2、Grow in 250 ml "SOB" at 18℃ until OD600 = 0.6.(0.3)接种于250ml SOB，18度培养至OD＝0.6。 3、On ice for 10 minutes.菌液置冰上10分钟。 4、Spin ...

1. Pick pl ...

Hi I looked for CpG islands within the promoter of my gene.MethPrimer and CpG plot analysis revealed that in this genes promoter region there were two big CpG islands at locations 280-603 and 693-859. ...

This is a modification of the procedure in Short Protocols (1-411-45) 1.Prepare a 50 ml liquid lysate: A.mix 2xlO8 E.coli cells with 100μl phage (from one picked plaque in 500μl SM)and 100μl ...