Glyoxal fixatives are rapid acting compared to formaldehyde.

• A. True
• B. False
• C. They act slower
• D. They are not fixatives

Answer: (A)

Glyoxal fixatives are able to stabilize tissue structure more quickly than formaldehyde because they form cross-links with proteins more rapidly once they diffuse into the tissue, especially in buffered formulations that optimize the reaction conditions. This faster cross-linking reduces the time needed to achieve adequate fixation, so tissues can be preserved effectively in a shorter period. In practice, you’ll often see glyoxal-based fixatives described as rapid-acting compared to formalin. Of course, the exact speed can vary with tissue type and the specific fixative formulation, but the general idea is that glyoxal fixatives fix more rapidly.