The BcaBEST DNA labeling kit is a novel random-primer labeling system that uses longer primers (9-mers) and BcaBEST polymerase, a thermostable DNA polymerase isolated from Bacillus caldotenax. Unlike the E. coli Klenow fragment (Feinberg and Vogelstein 1983; Feinberg and Vogelstein 1984) or modified T7 DNA polymerase, Bca polymerase allows stable polymerization of DNA even for templates with high GC content containing highly structured regions. Longer 9-mer primers increase the incorporation efficiency of labeled nucleotides up to 80%.

With this kit, random-primer labeling via thermostable Bca polymerase is accomplished in 10 minutes, resulting in high yields of labeled DNA probe. The kit is designed for use with [³²P]-alpha-, [³⁵S]-alpha-, or [³H]-alpha-dCTP labels, but it can also be used with nonradioactive biotin, digoxigenin, or DNP-labeled dUTPs through dNTP replacement. In general, probes with specific activities of >10⁹ dpm/mg DNA are obtained with [³²P]-alpha-dCTP (~3,000 Ci/mmol, 111 TBq/mmol).

Note: This kit was previously named the "Ladderman Labeling Kit". The kit components have not changed.