What Is Molecular Pathology

Molecular pathology is a discipline that combines traditional tissue-based diagnosis with molecular biology techniques to detect disease at the DNA, RNA, or protein level. It bridges morphological analysis, such as examining stained slides under a microscope, with genomic testing, enabling more precise diagnosis, prognosis, and treatment selection for conditions like cancer.

A biopsy is sent for molecular testing to identify specific genetic mutations, biomarkers, or expression patterns that guide diagnosis and treatment decisions. This is especially common in oncology, where molecular results can determine which targeted therapies or clinical trials a patient may qualify for, beyond what visual tissue examination alone can reveal.

Molecular pathology tests include DNA sequencing, RNA sequencing, PCR-based assays, and biomarker panels that analyze genetic material extracted from tissue samples. These tests detect mutations, gene expression changes, or infectious agents, often using techniques like laser capture microdissection—such as Laxco's Accuva Cellect, which uses a gentle IR laser and a UV laser to isolate pure cell populations before extraction and analysis.

PCR (polymerase chain reaction) based testing is among the most common molecular diagnostic methods, used for detecting infectious agents, genetic mutations, and gene expression changes. In oncology, targeted mutation panels and next-generation sequencing are also widely used to guide precision treatment decisions.

Laser capture microdissection (LCM), as performed by Laxco's Accuva Cellect using its gentle IR laser and UV laser, allows pathologists to isolate specific cells or regions of interest from a tissue slide without contaminating samples with surrounding tissue. Accuva Cellect uses a gentle IR laser for contact-free capture of single cells or small groups of cells, plus a UV laser for fast, precise cutting of dense structures. This produces purer genetic material, improving the accuracy of downstream sequencing, PCR, and other molecular tests compared to whole-tissue extraction methods.

Turnaround time varies by test type and laboratory workflow, ranging from a few days for targeted PCR panels to one to two weeks for comprehensive next-generation sequencing. Factors like sample preparation, cell capture method, and testing volume can all affect overall processing time.

Yes, formalin-fixed paraffin-embedded (FFPE) tissue blocks can be used for molecular testing. Specialized extraction and amplification protocols recover usable DNA and RNA from these archived samples, making retrospective studies and delayed molecular analysis possible even years after the original biopsy.

Molecular pathology technology is used by clinical pathologists, cancer researchers, academic laboratories, and pharmaceutical companies. It supports diagnostic testing in hospitals, biomarker discovery in research settings, and drug development programs that require precise, cell-type-specific genetic or protein data.