5. Implementation of Automatic Slide Processing for Aneuploidy FISH Test

Abstract

The AneuVysion FISH probe kit is FDA approved for detecting aneuploidy of chromosomes X, Y, 13, 18 and 21 on amniocytes (AF). Clinically, this kit is also used to identify numerical abnormalities in other specimen types, including chorionic villi sampling (CVS), cord blood, and peripheral blood. Currently, the majority of FISH tests in our lab have been adapted to the automatic slide processing system - BioDot instruments. Therefore, a validation was conducted to integrate the procedure of aforementioned Aneuploidy FISH test into the BioDot instruments. During the development phase, 34 cases were processed following the standard BioDot protocol with the exception of AF and CVS. Cell pellets from AF and CVS being manually applied onto slides due to the low cellularity. The FISH signal intensity and background were compared based on a 0 -7 scale. The FISH signal intensity was comparable between the slides processed by Biodot protocol and the lab current protocol (5.0 vs 4.8, p =4.8); the background score improved on the slides with the Biodot procedure (5.3 vs 5.1, p = 0.01). Subsequently, 21 cases for accuracy and 12 cases for precision (between run and within run) were tested on BioDot instruments for validation. These cases demonstrated 100% concordant FISH results with those from the current manual procedures. This study suggests that the traditional FDA-approved FISH Aneuvysion test can be seamlessly adapted to our standard Biodot FISH slide processing. This transition will streamline lab workflow, increase work efficiency, better FISH test quality and improve cost effectiveness.