DNA polymerase Taq is purified from bacteria culture. It contains trace amount of bacterial DNA, which may interfere PCRs using bacteria genomic DNA or bacterial DNA as templates. PureTaq is a further purified Taq, which removed any bacterial DNA 

• An optimized ready-to-use solution containing PureTaq DNA polymerase, standard Taq reaction buffer, dNTPs, tracking dyes and stabilizers. It is ideally suited to routine PCR applications such as sub-cloning, colony screening and genotyping. It can amplify up to 4 kb from complex genomic DNA or up to 5 kb from lambda DNA.
• Tracking dyes included in the mix: Blue dye migrates approximately 4 kb, and yellow dye migrates approximately 50 bp.
• 5x1ml, contains 250U PureTaq DNA polymerase