The Development of an IHC Service at a Tertiary Care Hospital

IHC service (IHC) combines anatomical, immunological and biochemical techniques to visualize discrete components within tissues by employing labeled antibodies that bind to their targets in situ. This allows the pathologist to examine tissue sections in their proper histological context and identify cellular processes such as cell differentiation, proliferation, apoptosis, metastasis, and more.

IHC is a common diagnostic procedure used to determine the status of cancer and other diseases, and also as a confirmatory tool for disease diagnosis. In addition, IHC is used extensively in research to identify cellular proteins and their functions in normal and diseased tissues.

IHC Services: A Guide to Immunohistochemistry Testing

As with any new service, the development of IHC at a tertiary care hospital in a rural setting required several building blocks to be put in place. These included establishing a functioning histology laboratory, importing and maintaining functional IHC equipment, training IHC technologists to perform immunohistochemical analysis, engaging external expertise in the development of resource-efficient protocols, and supporting staff to meet the requirements of an external quality assurance programme.

In order to obtain an accurate and reproducible IHC result, it is important that all specimens are carefully prepared. This includes the correct collection of samples, adequate specimen size for sectioning, and ensuring that the sample is fully penetrated by formalin. The use of appropriate negative and positive controls is also essential to validate results. The following example shows a sample from the tonsil, stained for Ki67, which is a nuclear marker for proliferating cells. This section was incubated with hematoxylin before the primary antibody, allowing the presence of the antibody to be detected. To improve the contrast between the hematoxylin staining and the red fluorescence of the primary antibody, this slide was counterstained with Thermo Fisher streptavidin-DyLight 633 conjugate (21844, red fluorescence) after the IHC antibody.