Knowledge base

While tissue must be properly fixed for staining methods to work well, the situation is slightly different with immunostaining. Immunohistochemical staining uses antibodies that target epitopes, specific parts of proteins that are recognized by the antibodies and bind to them. Formalin fixes tissues and proteins by producing cross-linking, which masks the epitopes!

You may have heard that regulations in Europe require manufacturers to offer containers that eliminate exposure to these vapors. In fact, exposure to formaldehyde fumes without the protection of a chemical hood is strictly forbidden there.

After multiple events of patient samples not being managed in an optimal fashion, guidelines were published in 2020 and updated in 2023 regarding fixation of breast tissue samples tested for ER/PR/Her2 expression. 

Histology has been processing tissue in essentially the same way for decades. It's a technique that works so well that it has little changed over time.

For a while now, histology laboratories have standardized tissue fixation using 10% neutral buffered formaldehyde. Proper fixation is essential because all the following laboratory procedures rely on adequate fixation to render quality results possible.