Calibration microarray that can be used for quantification and semi-quantification of immunochemistry slides for a multitude of biomarkers simultaneously.
- Higher level of comparability between immunohistochemistry slides.
- Higher level of fidelity of quantification of biomarkers in immunohistochemistry slides.
- Provides standardization for the subjective method of immunohistochemistry.
- Multiplexed ability to read multiple biomarkers quantitatively on a single slide.
Immunohistochemisty has a large role in the field of pathology and provides excellent details of tissue structure; however it is a highly subjective and qualitative technique that has inherent variability in staining. In addition, interpretation of the sample assay can vary between diagnostic labs which can contribute substantially to errors in clinical diagnoses. These erroneous diagnoses result in delayed or unnecessary procedures, missed diagnoses, and increased health care costs from additional tests and expensive procedures that may not have been necessary or appropriate. New technologies that measure the protein concentration more accurately may be required to achieve the accuracy required for companion diagnostics.
Quantum dots have become a popular visualization tool for immunohistochemistry, however they too exhibit a high degree of variability due to their emission of light. This variability makes the data obtained from quantum dot-immunohistochemistry assays difficult to compare between samples. A control is needed for the calibration of each sample assay to determine protein levels as well as compare different samples. Emory researchers have developed a calibration microarray, termed a pseudo-tissue microarray (PTMA) that contain ?pseudo-tissue? samples with known biomarker levels from cell lines that exhibit very high and very low expression levels to act as controls. In addition, the microarray includes positive and negative controls for tissue or cell samples. A critical advantage of this technology over existing technologies is that controls can act as standards for multiple markers simultaneously when using cell/tissue-based controls. Using this process, only two homogenates are needed i.e. those that are negative for all markers and those that are highly positive for all markers. By using this technology, quantitative multimarker profiling of more than three biomarkers is possible in minute, clinical samples.
Proof of concept studies have shown that staining intensity in controls is highly correlated with biomarker content.