The HotStart Polymerase Modification Kit provides an easy way to reversibly modify lysine residues of thermostable DNA polymerase, rendering the enzyme inactive. The modification is reversed after heating to >90°C. HotStart modification of DNA polymerase for PCR prevents amplification of non-specific PCR products due to low stringency annealing of primers at low temperature during reaction assembly. The trial size kit (29054-T) is sufficient for modifying 0.1 mg polymerase, while the regular size kit (29054) is sufficient for modifying 0.5 mg polymerase. Biotium also offers the WarmStart™ Enzyme Modification Kit (catalog no. 29053) for temperature control of non-thermostable enzymes. For concentration measurement of polymerase before modification, we offer the AccuOrange Protein Quantitation Kit for highly sensitive fluorometric measurement of purified protein concentration.