iSlideGuard: Automation of 2” x 3” Slide Coverslipping
Kamalasaravanan Sargunam Prakash, Prabhakar Sithambaram, Ramdayalan Kumarasami, Sathishpandidurai Arunachalam, Prithviraj Perumbattill Rajan, Mohanasankar Sivaprakasam, Jayaraj Joseph · 2025
Coverslipping is a critical process in determining the quality of the histological slides, where tissue sections mounted on glass slides are coated with a transparent adhesive and covered with a thin (0.17 mm) coverslip glass. This protects the tissue and enhances its optical clarity for microscopic analysis. Even today, in many laboratories, manual coverslipping is predominant and is prone to errors such as air bubble formation, inconsistent application of mounting media, misaligned coverslips, and breaking when mishandled, leading to compromised sample quality. Automating this process could improve consistency, reduce errors, and increase throughput in laboratories. Commercially, coverslippers are available, which only cater to 1” x 3” slides, thereby limiting the size of the tissue that can be analyzed. The primary goal is to develop and validate a fully automated coverslipping system capable of batch-wise processing of 2” x 3” tissue slides ― a significant advancement, as no existing systems currently support batch-wise automation for this slide size. iSlideGuard is an automated coverslipper for 2” x 3” slides that employs sensor-guided feedback mechanisms for accurate slide detection, pressure-controlled suction for coverslip handling, optimized dispensation of transparent adhesive, and a unique Scotch yoke mechanism for coverslip picking and bubble-free placement. The system can coverslip 13 slides in a single batch, with a throughput of 45 slides per hour. The iSlideGuard system demonstrated consistent mountant application (0.3 ml per slide) and reliable suction pressure maintenance within the range of −19 kPa to −23 kPa (critical for safer coverslip handling), resulting in bubble-free coverslipped slides. Out of 13 slides with fetal brain tissue that were coverslipped in the iSlideGuard, only one had air bubbles. The system significantly improves the consistency of coverslipping for 2” x 3” tissue slides, reducing manual errors and enhancing productivity in histopathology workflows, with batch-wise loading and a unique Scotch yoke mechanism, making it an invaluable tool for high-throughput laboratories.