Genetic Diagnostic Tests | Pathwork Diagnostics Microarrays Technology

Tissue of Origin Test
Microarray Technology

About microarray, our core technology

Until recently, microarray has been used primarily as a research tool. Now, Pathwork Diagnostics is helping to usher in a new era in which microarray is used in clinical diagnostics. The company’s unique processes use microarray-based data to enable the development of clinically useful diagnostic offerings in oncology.

Microarray consists of probes that are arranged or "arrayed" on a glass chip. These probes are small fragments of DNA that represent a section of a specific gene's entire DNA sequence. Microarray is a robust tools for gene expression diagnostics because it measures expression levels of large numbers of genes simultaneously and can answer multiple diagnostic questions with one array.

Pathwork has developed unique processes that enable the company to bring microarray data from the realm of research into practical daily clinical use—solving critical technological challenges such as:

Obtaining meaningful and easy-to-interpret information from highly complex data sets
Working with heterogeneous tissues that include variable amounts of tumor
Developing the ability to work with FFPE tissue specimens that may contain degraded RNA
Normalizing gene expression patterns for consistency across different instruments with different operators
Incorporating reliable and effective data quality control processes
Providing the combination of microarray, instrumentation and informatics in a reliable system that ensures diagnostic-quality data every time

Pathwork’s unique microarray-based data technologies enable the Tissue of Origin Testing Service to measure the expression pattern, comprising nearly 5,000 genes, in a challenging tumor. The test compares it to expression patterns of a panel of 17 known tissue types, representing 95% of all solid tumors, in order to identify the primary tumor type

Testing tumors: RNA is extracted from a sample of tumor tissue. The target is prepared from the RNA, labeled with a fluorescent marker, and spread over the surface of the chip. The target binds to complementary gene-specific probes on the array, in a process called hybridization. The relative fluorescence intensity of each gene-specific probe is then measured. The greater the degree of hybridization, the more intense the signal, indicating an increased level of expression of that gene.