Application of Chromogenic In Situ Hybridization (CISH) for Human Papillomavirus (HPV) Genotyping

Obvious decreasing in cervical cancer mortality has been observed in countries with organized cervical cancer screening programs [1]. Liquid based cytology is a technique that enables cells to be suspended in liquid medium and spread in monolayer for better morphological assessment. It includes the preparation and evaluation of cells collected in liquid fixative. It is being introduced to improve the sensitivity of the Pap test [2]. Liquid based preparations are increasingly being used both for gynecologic and non-gynecologic cytology, including fine needle aspirations [3]. Two technologies, ThinPrep (Hologic, Marlborough, MA, USA) and BD Sure Path (BD Diagnostics – TriPath, Burlington, NC, USA) have been more widely used [2]. The advantages of liquid based cytology include improved sensitivity and specificity since fixation is better and nuclear details are well-preserved. Abnormal cells are not obscured or diluted by other epithelial or inflammatory cells. There is, therefore, a lower rate of unsatisfactory cervical cytology samples. The residual cell suspension can be used to make further cytological preparations or used for other tests like detection of human papillomavirus DNA. Other ancillary techniques like immunocytochemistry can also be performed on the residual sample [4]. The more widely used technologies for liquid based cytology require expensive equipment [2].