Thermo Scientific™ T4 Polynucleotide Kinase (T4 PNK) catalyzes the transfer of the gamma-phosphate from ATP to the 5'-OH group of single- and double-stranded DNAs and RNAs, oligonucleotides, or nucleoside 3'-monophosphates (forward reaction). The reaction is reversible. In the presence of ADP, T4 Polynucleotide Kinase exhibits 5'-phosphatase activity and catalyzes the exchange of phosphate groups between 5'-P-oligo-polynucleotides and ATP (exchange reaction). The enzyme is also a 3'-phosphatase.

Highlights
• Active in Thermo Scientific restriction enzyme, RT, and T4 DNA ligase buffers

Applications
• Labeling 5' -termini of nucleic acids to be used as:
    --Probes for hybridization
    --Probes for transcript mapping
    --Markers for gel electrophoresis
    --Primers for DNA sequencing
    --Primers for PCR
• 5'-phosphorylation of oligonucleotides, PCR products, other DNA or RNA prior to ligation
• Phosphorylation of PCR primers
• Detection of DNA modification by the [³²P]-postlabeling assay
• Removal of 3'-phosphate groups

Notes
• The 5'-termini of nucleic acids can be labeled by either the forward or the exchange reaction.
• Polyethylene glycol (PEG) and spermidine improve the rate and efficiency of the phosphorylation reaction. PEG is used in the exchange reaction mixture.
• Since T4 Polynucleotide Kinase is inhibited by ammonium ions, use sodium acetate to precipitate DNA prior to phosphorylation.