Gelelectrophoresis(凝胶电泳) 1. Gel electrophoresis separates DNA and RNA molecules according to size, shape and topological properties
7 1. Gel electrophoresis separates DNA and RNA molecules according to size, shape and topological properties Gel Electrophoresis （凝胶电泳）
DNA gel mobility(DNA在胶上的迁移性 1.DNA and RNA molecules are negatively charged, thus move in the gel matrix(胶支持物) toward the positive pole(正电极) 2. Linear DNA molecules are separated according to sizes. The large dna molecules move slower than the small molecules 3. The mobility of circular DNA molecules is affected by their topological structures. The mobility of the same molecular weight DNA molecule with different shapes is: supercoiled(超螺旋)> linear(线性)> nicked or relaxed(缺刻或松散)
8 1.DNA and RNA molecules are negatively charged, thus move in the gel matrix (胶支持物) toward the positive pole (正电极). 2.Linear DNA molecules are separated according to sizes. The large DNA molecules move slower than the small molecules. 3.The mobility of circular DNA molecules is affected by their topological structures. The mobility of the same molecular weight DNA molecule with different shapes is: supercoiled (超螺旋)> linear (线性) > nicked or relaxed (缺刻或松散) DNA gel mobility (DNA在胶上的迁移性)
DNA can be visualized by staining the gel with fluorescent dyes, such as ethidium bromide(EB溴化乙锭) electrophoresis chamber buffer solution DNA fragments agarose gel electrode electrode large moderate small Fig 20-1: DNA is separated by gel electrode electrode electrophoresis small dNA fragments move further through the gel than large fragments Copyright 2004 Pearson Education, Inc, publishing as Benjamin Cummings
9 Fig 20-1: DNA is separated by gel electrophoresis large moderate small DNA can be visualized by staining the gel with fluorescent dyes, such as ethidium bromide (EB 溴化乙锭)
Gel matrixκ(胶支持物) Gel matrix(胶支持物) is an inserted jello-like porous material that supports and allows macromolecules to move through 10
10 Gel matrix (胶支持物) is an inserted, jello-like porous material that supports and allows macromolecules to move through. Gel matrix (胶支持物)
Polyacrylamide(聚丙稀酰 胺): (1)has high resolving capability and can MgCh(mM) resolve DNA/RNa that 0204060811215235710 differ from each other mana ERli- as little as a single base pair/nucleotide nissan ===== (2)but can separate DNA over a narrow size range〔 up to a few 三= hundred bp/nt)
11 Polyacrylamide (聚丙稀酰 胺): (1)has high resolving capability, and can resolve DNA/RNA that differ from each other as little as a single base pair/nucleotide. (2)but can separate DNA over a narrow size range (up to a few hundred bp/nt)