Enzyme purification step DNA pol β–specific catalytic activity, [3H]DNA c.p.m./mg protein (M ± SEM, n=6)
Total cell homogenate 588 ± 63
Crude nuclei (P0.8) 1,864 ± 87
Crude chromatin 2,476 ± 118
Phenol-chloroform extraction 6,081 ± 202
Ammonium sulfate 30%-70% saturation gradient 10,112 ± 233
Diaflo Y5.0 ultrafiltration 19,423 ± 270
TOYOPEARL HW 55F Gel Chromatography 32,687 ± 331
Table 2: An increase of DNA pol β activity in a multi–step purification procedure