ABSTRACT
BACKGROUND: Polymerase chain reaction (PCR) is known as a sensitive and specific method for the detection of varicella-zoster virus (VZV). Nested PCR is reliably used than conventional PCR to increase the sensitivity and specificity, especially in cases of small sized tissue samples. METHODS: We detected VZV infection in tissues from 111 patients using conventional PCR and nested PCR. Ninety-one cases of fresh tissues and twenty cases of formalin-fixed paraffin-embedded (FFPE) tissues were evaluated. The column method or home made lysis buffer method was used for the DNA extraction of fresh tissues and FFPE tissues. RESULTS: Among total 111 cases, VZV were detected in 62 (55.9%) cases by conventional PCR and 79 (71.2%) cases by nested PCR. The detection rate of nested PCR was higher than conventional PCR (1.27 folds). In 91 cases of fresh tissues, 56 (61.5%) were positive by conventional PCR and 68 (74.7%) by nested PCR. In 20 cases of FFPE tissues, 6 (30%) were positive by conventional PCR and 11 (55%) by nested PCR. The detection rate of VZV was increased by nested PCR both in fresh tissues (1.21 folds) and FFPE tissues (1.83 folds). CONCLUSIONS: Nested PCR is the more sensitive method than conventional PCR for the detection of VZV infection in tissues regardless of DNA extraction methods, especially for the small sized FFPE tissues.