FAQ: Is SP6 RNA Polymerase an enzyme of choice for making high specific activity labeled probes?

Yes, SP6 RNA Polymerase, T7 RNA Polymerase (NEB# M0251), and the HiScribe T7 In Vitro Transcription Kit (NEB# E2030 ) can be used to make RNA probes. Increased levels of detection in nucleic acid hybridization can be obtained due to the greater stability of RNA: DNA hybrids with respect to DNA: DNA hybrids (1). The NEBlot Kit (NEB# N1500) can be used for making high specific activity DNA probes using random primers. Klenow Fragment (3'→5' exo-) (NEB# M0212) can be used with the same procedure and a specific primer.
(1) Zinn, K et al. (1983) Cell 34, 865-879.