琼脂糖电内渗对电泳的影响

用电内渗不同(0、0.03、0.08、0.20mr)的琼脂糖制成凝胶或电极缓冲液凝胶条,观察对电泳行为的影响.结果表明等电聚焦电泳必须使用无电内渗琼脂糖.不同电内渗的琼脂糖制成的电极缓冲液凝胶条对SDS电泳无显著影响,但对常规聚丙烯酰胺凝胶电泳有不同程度的影响,电内渗越高,越不利于电泳的进行.     

Electroelution of lipoprotein(a) [Lp(a)] from native polyacrylamide gels: a new, simple method to purify Lp(a)

Lipoprotein(a), Lp(a), is an atherogenic lipoprotein consisting of an LDL like core particle and a covalently linked glycoprotein of variable size. Lp(a), isolated from serum always contains LDL and HDL(2) as contaminants since Lp(a) floats in the density range 1.05-1.12 g/ml which overlaps that of LDL and HDL(2). Purified Lp(a) is increasingly needed as a standard to overcome various problems in the standardization of Lp(a) measurements and for in vitro biological studies. Problems inherent to the purification of Lp(a) include the aggregation of Lp(a) with LDL, overlapping size distribution and the inability of some fractions to bind to affinity columns. Here, we describe the development of a new method to purify Lp(a) from contaminating LDL and HDL(2) particles. Lp(a) was isolated from serum by sequential ultracentrifugation, resolved by native polyacrylamide gel electrophoresis and the gel segments were electroeluted to obtain pure Lp(a). l-Proline was added to the sample to a final concentration of 0.1 M to prevent the aggregation of Lp(a) with LDL.     

Two-dimensional restriction mapping by digestion with restriction endonucleases of DNA in agarose and polyacrylamide gels

We have studied with a number of bacterial restriction enzymes the conditions for digestion of DNA in agarose and polyacrylamide gels. The restriction endonucleases HpaII, MspI, HaeIII, HindIII, TaqI, HhaI, AluI, BamHI, EcoRI and SalI are capable of digesting DNA in agarose gels of low electroendosmosis and low sulfate concentration. All enzymes, except BamHI, are also capable of digesting DNA in polyacrylamide gels. With this method, rapid two-dimensional restriction mapping of genomes with low and high sequence complexity is possible.