Which histological technique involves staining tissue to visualize pathogens?

Immunohistochemistry is a powerful histological technique that utilizes specific antibodies to detect and visualize the presence of pathogens within tissue samples. This process involves applying these antibodies to the tissue sections, which then bind to specific antigens associated with the pathogens. Following this binding, secondary antibodies conjugated with detectable labels (like enzymes or fluorescent dyes) are introduced, allowing for visualization under a microscope. This technique is particularly valuable in identifying infectious agents, such as bacteria and viruses, as well as in diagnosing various diseases, including cancers, by highlighting abnormal protein expression within tissues.

In contrast, histochemistry primarily focuses on the detection of chemical components within cells and tissues using various staining methods, but it does not specifically target pathogens. Fluorescent microscopy is a technique that enables the visualization of samples using fluorescent dyes but is not exclusively tailored for pathogen detection unless combined with immunohistochemistry. Transmission electron microscopy provides ultra-structural images at a very high resolution, primarily visualizing cellular components rather than directly staining pathogens in the context of histological evaluations.