IHC Testing

what is immunohistochemistry

Overview

Immunohistochemistry (IHC), also known as immunostaining, is a routine but essential tool in diagnostic and research laboratories.

 

The process involves staining thin sections of tissues attached to glass slides.  IHC staining makes it possible to selectively identify clinically important protein biomarkers in the cells of the tissue section. The outcome allows you to visualize and document the distribution and localization of specific cellular components within cells.

what is immunohistochemistry

Applications

Immunohistochemistry (IHC) staining is widely and effectively used for diagnosing diseases such as abnormal cells in tissue samples with cancerous tumors. It is also used in deciding which treatment will be most effective for treating certain cancers.

 

IHC is also used in biological research in a variety of different ways, including normal tissue and organ development, pathological processes, wound healing, cell death and repair, and understanding the distribution and localization of biomarkers, to name a few.

 

IHC is also used in pharmaceutical research and development to evaluate drug efficacy and safety as well as identify patients who will likely benefit from a particular treatment.

immunohistochemistry, tissue sampling

The Problem

Immunohistochemistry (IHC) is an indispensable tool for molecular pathological diagnosis. However, it is an unfortunate truth, per numerous published journal articles, that Clinical IHC testing suffers from high error rates. (Reviewed in ref. 1)

 

In most clinical laboratory disciplines, the error rate is less than one percent (1).  However, in Clinical IHC testing, published studies reveal an error rate that is sometimes as high as 30 percent.  This complicates diagnosis and can lead to inappropriate patient management.

 

The high error rate can be largely attributed to the lack of consistent, easy-to-use, high-quality positive reagent controls and calibrators (1). The biggest problem with Clinical IHC controls is that the lab does not select controls with sufficiently low concentrations of analyte.  High analyte concentrations in a control create an aesthetically pleasing, strong appearance but are profoundly insensitive.  In addition, Class II or III IHC tests should always have on-slide controls.  The cost and difficulty of doing this, however, results in inconsistent adherence to regulatory guidelines. The time needed to identify, prepare, and test homemade controls is a drain on lab resources. Homemade controls are also inherently variable and are of unknown analyte concentration.

 

Purchasing on-slide controls in a ready-to-use format, with analyte concentrations already optimized to your immunostain, improves performance, simplifies compliance, and lowers your costs.

 

(1) SA Bogen. A Root Cause Analysis Into The High Error Rate In Clinical Immunohistochemistry. Immunohistochem. Mol. Morphol. 2019. In press.

immunohistochemistry calibrators, IHC calibrators

The Solution

Historically, the adoption of standardized controls and calibrators with concentrations traceable to an international standard was associated with a dramatic decline in clinical laboratory error rates in Clinical Chemistry, Immunology, and Hematology (1).  Boston Cell Standards brings the same tried and tested solutions to Clinical Immunohistochemistry.

 

IHControls are on-slide IHC staining controls that use proprietary tagged peptide targets, which provides for analytic traceability to an international concentration standard (2). This assures consistency day-to-day, lot-to-lot, and lab-to-lab.  IHControls’ performance in checking primary antibodies, detection kits, and antigen retrieval has been validated and published (3-5).

 

IHCalibrators are similar in construction but provide for precise measurement of the limit of detection, the most important parameter of analytic sensitivity.  With IHCalibrators, clinical IHC laboratory staff can ensure that their immunostain is configured correctly, capable of sensitively detecting the cellular biomarker in question.

 

The result is that IHControls and IHCalibrators place the clinical IHC lab on par with other types of clinical diagnostic labs, which already have commercial standardized test controls.

 

In addition to reduced error rate, the fact that IHControls can be easily purchased off-the-shelf means labs can finally eliminate the time-consuming task of producing inconsistent, non-standardized homemade tissue controls. IHControls have been extensively tested and validated, as described in a series of published papers.

 

 

(2) K Vani, et. al. Analytic response curves of clinical breast cancer IHC tests.  J. Histochem. Cytochem. 2017 65(5):273-283.

(3) SR Sompuram, et. al. Quantitative assessment of immunohistochemistry laboratory performance by measuring analytic response curves and limits of detection.  Arch. Pathol. Lab. Med.2018 142(7):851-862.

(4) K Vani, et. al.  The importance of epitope density in selecting a sensitive positive IHC control. .J. Histochem. Cytochem. 2017 65(8):463-477.

(5) SR Sompuram, et. al. Selecting an optimal positive IHC control for verifying antigen retrieval.  J. Histochem. Cytochem. 2019 67(4):275-289.