To create a DNA probe

To create a DNA probe labelled with 32-$$\mathrm{P}$$at the 5′ ends, The DNA segment is dephosphorylayted using alkaline phosphatase followed by addition of 32P from gamma labelled ATP using polynucleotide kinase

The DNA segment is dephosphorylayted using alkaline phosphatase followed by addition of 32P from alfa labelled ATP using polynucleotide kinase The DNA segment is dephosphorylayted using Klenow polymerase, followed by addition of 32P from beta labelled ATP using polynucleotide kinase