troduce different notations. Some consider “NTP” a general term for deoxynucleotides, but the absence of the letter “d” indicates a ribonucleotide to others. Commercial literature also describes ribonucleotides as “RTP’s.” If the letter “d” is present, the name describes a deoxynucleotide. If “d” is absent, check the literature

Air Buoyancy Akin to water keeping something afloat, samples can be “lifted” by air, artificially decreasing their apparent weight. This air buoy￾ancy can have a significant effect on smaller samples. Electrostatic Forces Electrostatic charges are almost always present in any environ￾ment, particularly in areas with very low humidity. If there are

This book celebrates the importance of the question; it is not meant to be a collection of facts or procedures. The writing of this book was inspired by 16 years of queries from the research community.The con￾tributors and I have tried to meet two primary objectives:

What Are the Symptoms of Acrylamide Poisoning? The initial symptoms of acrylamide poisoning on the skin are peeling of the skin at the point of contact, followed by tingling and numbness in the exposed area. If exposure by any means (touch, ingestion, inhalation) continues, muscular weakness, difficulty maintaining balance

How Important Is Cost? Reagents obviously figure into the cost of a procedure, but the labor required to produce and apply the reagents of purification should also be considered. How Important Is Reproducibility (Robustness) of the Procedure?

一、基因表达的概念 1、基因（gene）：从遗传学讲，基因就是遗传的基本单位或单元，具有编码RNA或多数情况下编码多肽功能的信息单位。从分子生物学看，基因是负载特定遗传信息的DNA分子片段

一、三种不同的RNA聚合酶 二、RNA 聚合酶的组成 三、真核RNA聚合酶的活性

一、顺式作用元件和反式作用因子 Cis-acting element：不编码任何产物的 DNA片段，能影响与之相联系的同一条 DNA链上的基因表达 :启动子。 Trans-acting factor （转录因子TF） 由调节基因编码，调节基因是一种特殊 的结构基因，其编码产物（RNA或蛋白质） 可以扩散，控制其他基因的表达

Translation is the conversion of the information in the nucleic acid sequence to polypeptides of a specific amino acid sequence

In both prokaryotes and eukaryotes, primary RNA transcripts undergo various alteration or processing events to become mature RNAs: The three commonest types are: 1, nucleotide removal by nucleases; 2, nucleotide addition to the 5’- or 3’-end, 3, nucleotide modification on the base or thesugar