Detection of transfusion transmitted virus(TTV)DNA using DIG labeled probe prepared by polymerase chain reaction

Objective To study the sensitivity and the specificity of digo xigenin(DIG)labeled DNA probe for detection of TTV DNA. Methods The probe was directly prepared from products of polymerase chain reaction(PCR). TTV DNA was detected by dot blot hybridization,and then the sensitivity and the specificity of the probe was compared with that of the nested-PCR(nPCR). Results The sensitivity of the DIG-DNA probe was 10 pg TTV DNA. 108 sera and 22 feces of patients with non A ～G hepatitis were tested by dot blot hybridization. The positive rate of TTV DNA was 18. 5%(20/108)for sera,and 27. 3%(6/ 22)for feces,respectively. The total coincidence rate between the dot blot hybridization and the nPCR was 96.9%(1 26/ 1 30). Conclusion The direct prearation of DIG-labeled TTV-DNA probe by PCR is much faster and more simple than the traditional method of labeling. The presence of TTV in feces of patients with TTV infection indicates the possibility of fecaloral transmission of the virus.