Development and use of a DNA probe for confirmation of cDNA from infectious salmon anaemia virus (ISAV) in PCR products

Infectious salmon anaemia virus in fish tissues or cultured cells can be de tected by polymerase chain reaction amplification of part of genome segment 8. An oligonucleotide probe complementary to sequence within this PCR prod uct was designed. The probe was labelled with digoxigenin and hybridised to PCR products that had been immobilised on a membrane by Southern blotting. The probe provided greater sensitivity than visual examination of PCR prod ucts in ethidium bromide stained gels and provides a means to confirm that PCR products of approximately the size expected for infected samples are sp ecific.