In Situ Hybridization, with or Without Tyramide Signal Amplification, in Evaluation of Human Papillomavirus Status Inearly Stage Cervical Carcinoma

Abstract

Conventional in situ hybridization (CISH) can be used for detection of human papillomavirus (HPV) DNA, enabling preservation of the tissue morphology and assessment of the physical state of viral DNA, but has low sensitivity. This study compared the sensitivity and efficiency of in situ hybridization with tyramide signal amplification (ISH TSA) with those of CISH. The HPV status of 77 cases with early stage cervical carcinoma was evaluated with CISH, using biotinylated probes for HPV types 6/11, 16/18 and 31/33/51, and with ISH TSA using probes for HPV types 6/11, 16/18 and 31/33 or 31/33/51. The HPV DNA was detected in 26 (33.8%) cases using CISH, and in 45 (58.4%) cases using ISH TSA. By adding the TSA step, the sensitivity of CISH was enhanced by 24.7%, thus enabling detection of 20 new HPV-positive cases. Multiple HPV infections were detected in four cases. A dot signal pattern was present in 68.9% (31/45) and more than five positive nuclei per sample were found in 82.2% (37/45) of the cases. We found that the ISH TSA system is a fast and simple method for detection of HPV DNA in cervical carcinoma compared to CISH, and is more sensitive and efficient in the detection and typing of HPV, assessment of HPV DNA physical state and evaluation of the number of positive cells than CISH.

Enhanced detection of Porcine reproductive and respiratory syndrome virus in fixed tissues by in situ hybridization following tyramide signal amplification

“…The development of TISH provides potential detection of low-and single-copy nucleic acid sequences. [6][7][8]16,21 In the present study, we compared the analytical sensitivity of TISH with CISH and IHC methods for the detection of PRRSV in infected lung tissue.…”

“…16 In recent years, the biotinyltyramide-based ISH (TISH) method has become widely used; TISH permits the detection of low copy number nucleic acids even in PE tissues. [6][7][8]21 Formalin is a commonly used fixative agent that inactivates most infectious agents and inhibits autolysis. 9,19 Formalin fixation results in the cross-linking of tissue protein with DNA or RNA; overfixation can reduce the sensitivity of IHC and ISH.…”

“…16 In recent years, the biotinyl–tyramide-based ISH (TISH) method has become widely used; TISH permits the detection of low copy number nucleic acids even in PE tissues. 6-8,21…”