INTRODUCTION

INTRODUCTION
Thermostable DNA polymerases are in high demand due to their applicability to new techniques in molecular biology, such as the polymerase chain reaction (8,10). Since these enzymes are derived from thermophilic bacteria, early purification schemes required the growth of large quantities of these thermophiles under unconventional conditions (3). The advent of biotechnology not only allows overexpression of such enzymes in standard E. coli, but also allows us to take advantage of the thermostable nature of the enzyme during the purification process (4,7,10). Described here is a simplified version of the cloning and purification procedure of T. aquaticus DNA polymerase overexpressed in E. coli originally developed by Lawyer et al. (7). This simplified procedure is a single step process that yields 10⁷ units of enzyme activity from a 100 mL culture of cells and requires no specialized equipment.