title: [Purification of Taq DNA polymerase expressed in Escherichia coli].
abstract: Taq DNA polymerase is one of the most commonly thermostable DNA polymerases in molecular biological researches, which shares its basic characters with others of the family, thereby its purifying strategy could be used not only in itself production but also in the extraction of the others as a reference. At present, the protocols reported for large scale preparation of Taq DNA are high cost, so a cheaper method was described here. In this protocol, by heat denaturation, ammonium sulfate precipitation and cation exchange chromatography of 724 resin, about 18 g powder of Na form resin could recover about 27.07 mg of Taq enzyme. The total activity and specific activity were approximately 2.2 × 10⁵ U and 8131.98 U/mg. The total yield was about 48.92% with 59.35 of purification folds. Analysis of quality of purified enzyme indicated that only one protein 94 kDa was identified against SDS-PAGE and the remnant of DNA nuclease was not detected. For PCR reaction, The amplification ability of purified Taq polymerase was not different from that of the commercially avail-able ones. This method reported in the present study is effective and low cost, making it suitable for general purification in laboratories or business production.
authors.affiliation: School of Food and Bioengineering, Jiangsu University, Zhenjiang 212013, China. tianlei_liu@hotmail.com
authors.forename: Tian-Lei
authors.initials: TL
authors.lastname: Liu
authors.forename: Shou-Bin
authors.initials: SB
authors.lastname: Xue
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Lin-Ying
authors.initials: LY
authors.lastname: Zhu
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Liang
authors.forename: Sheng-Xuan
authors.initials: SX
authors.lastname: Qu
authors.forename: Wen-Bo
authors.initials: WB
authors.lastname: Cai
mesh_terms: D002411:Cation Exchange Resins / Q000737:chemistry; D002852:Chromatography, Ion Exchange / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D015870:Gene Expression; D016133:Polymerase Chain Reaction; D013379:Substrate Specificity; D019914:Taq Polymerase / Q000235:genetics* / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D002411:Cation Exchange Resins; D019914:Taq Polymerase