Role of dry ice in decoverslipping of microscopic slides: A new insight

The process of decoverslipping is often required in a laboratory to review or examine an older slide which tends to fade over time, making it almost impossible to use it for research or study purposes. The sections then need to be re-stained which can only be done after removing the coverslip. The traditional method of decoverslipping using xylene is a time-consuming process. Various methods have been used in the past; however, none were found to be completely effective. Dry ice, the solid form of carbon dioxide, is an easily available, cheap cooling agent with a low freezing temperature (-78.5°C) which was evaluated for its efficacy in decoverslipping process, as an alternative to xylene.

64 faded haematoxylin and eosin (H&E)-stained histopathology slides were randomly selected and segregated, according to duration of year, into eight major groups. Each group was further divided into four subgroups according to the time that the slides were subjected for decoverslipping. The slides were placed on dry ice and the time was set. Once the coverslip was removed, the slides were placed in xylene to remove any residual mountant. The tissue sections were evaluated for physical disfigurement followed by re-staining with H&E to check for any change in tissue morphology.

The mean time taken for removal of coverslip using dry ice was 35 seconds.

This technique is easy, fast, and effective, with no tissue loss or compromise in staining quality, thereby preventing xylene toxicity and its effect on the environment.