Which statement about B5 fixative is true?

• A. Enhances immunoreactivity
• B. Destroys nuclear detail
• C. Causes excessive tissue shrinkage
• D. Is non-additive

Answer: (A)

B5 fixative is valued for preserving antigen sites so that antibodies can bind more effectively during immunohistochemistry. By fixing tissue with a milder approach that keeps epitopes accessible, it tends to enhance immunoreactivity, providing stronger and more reliable staining than fixatives that heavily cross-link proteins and mask epitopes. This makes it especially useful when immunostains are planned, while still maintaining good nuclear detail. The notion that it destroys nuclear detail or causes excessive shrinkage isn’t characteristic of its intended advantage, and its classification as additive or non-additive isn’t the defining point here. In short, the primary benefit of B5 is improved antigen preservation leading to better immunostaining.