[Construction of probes for hybridization with hepatitis A virus RNA based on phage M13]

Three fragments of a DNA copy complementary to tre hepatitis A virus RNA have been isolated from the pHAV-VPI-22 plasmid and cloned in M 13 mp 8 vector. The 140, 250 and 390 b. p. fragments corresponded to the viral genome fragment coding for VP1 protein. Single-stranded DNAs of the hybrid phages with 250 b. p. and 390 b. p. inserts have been used for radioactive probe synthesis. The specificity of the probes for viral RNA was confirmed in hybridization with hepatitis A virus RNA purified from the virus-infected cell culture. The hybridization was shown to detect up to 10(-12)-10(-13) g of the virus. A principal possibility to use the probes in diagnostic purposes was demonstrated by the virus detection in blood samples obtained from patients with hepatitis A infection.