IN-SITU POLYMERASE CHAIN-REACTION DETECTION OF VARICELLA-ZOSTER VIRUSIN INFECTED-CELLS IN CULTURE

Polymerase chain reaction (PCR) technology provides a means of identif ying genes and studying their expression with specificity and precisio n. Combined with in situ hybridization (ISH), the amplified gene can b e localized within cells. Cell gene sequences (human cr-tubulin) were identified by PCR-ISH first in uninfected cells in culture, then in hu man blood mononuclear cells, and finally in sections of human liver. V aricella tester virus (VZV) DNA was detected for the first time in vir us-infected cells in culture by PCR-ISH, and compared to ISH alone. Ef ficient PCR-ISH was achieved by fixation of cells or tissue sections w ith 2% paraformaldehyde, by amplification under conditions of complete exposure of the samples to the reagents, and by detection of amplifie d products using non-radioactive digoxigenin-labeled oligonucleotide p robes internal to the amplified DNA segment. PCR-ISH increased the det ection of VZV DNA in infected cells 5-fold compared to ISH alone. Comp ared to ISH alone, PCR-ISH enhances significantly the detection of vir us DNA in infected cells.