DNA Polymerase I, Large (Klenow) Fragment is a DNA polymerase enzyme that lacks the 5' to 3' exonuclease activity of intact DNA Polymerase I, but does exhibit the 5' to 3' DNA polymerase and 3' to 5' exonuclease activities.

Applications:
Fill-in of 5´ overhangs (1). Synthesis of probes by random primers labeling method (2). Sequencing single- and double-stranded DNA (3). Site-directed mutagenesis.

Source:
Purified from E. coli expressing the Klenow fragment on a plasmid.

Performance and Quality Testing:
SDS-PAGE purity; single-stranded and double-stranded endodeoxyribonuclease and self-priming assays; performance evaluated in fill-in reaction.

Unit Definition:
One unit incorporates 10 nmol of total deoxyribonucleotide into acid-precipitable material in 30 min. at 37°C using a template•primer.