Production of digoxigenin-labelled parvovirus DNA probe by PCR.

A 560-bp digoxigenin(Dig)-labelled DNA-probe was produced by PCR using a 699-bp parvovirus DNA fragment as template with introduction of Dig-dTUP into the PCR reaction mixture. It was found to be very important to pay close attention to the amount of template employed, the number of cycles used, predenaturation of target DNA and optimization of the percentage of dTTP substituted by Dig-DUTP in the reaction mixture. The same 560-bp DNA fragment produced by PCR without the incorporation of Dig-DUTP in the reaction mixture, was subsequently labelled with Dig-dUTP by the random primed labelling method. Both of the Dig-labelled parvovirus DNA probes described above showed the same DNA detection level (about 1 pg), but production of the probe with Dig-DUTP incorporated in the PCR reaction mixture was much simpler.