Tissue Processing: A Cornerstone to Quality Downstream Testing

Since the 19th century, the practice of tissue processing has remained largely unchanged, resulting in solidified, paraffin-embedded tissue blocks for sectioning. As staining procedures have advanced and immunohistochemistry is becoming more widely used, high-quality tissue sections are paramount for accurate interpretation of disease processes. At each processing stage, many variables require consideration to eliminate artifacts and preserve tissue morphology to ensure high-quality sectioning. This talk will review basic strategies to develop best laboratory practices and protocols from the beginning of the histology workflow, which results in good quality sections to minimize the need for repeat downstream testing.

Once the tissue has been processed well, getting good sections placed onto the glass slide should be easier; however, this is not always the case, with some cases proving challenging to cut. In this section of the talk, we will review the basics of embedding and sectioning, including paraffin types, molds, blades, and slides, as well as a discussion of artifacts. We will then present the “tricks of the trade” or “histology hacks” that almost every seasoned histologist has kept secret until now.