Molecular diagnostics focuses on analyzing genetic and molecular features of diseases at the DNA, RNA, and protein levels to provide highly specific diagnostic, prognostic, and therapeutic information. These techniques identify gene mutations and expression patterns that drive disease processes—particularly in cancer, infectious diseases, and inherited conditions.

Molecular testing may include targeted assays (such as PCR-based tests) to detect specific mutations, as well as broader platforms like next-generation sequencing (NGS) that can evaluate dozens to hundreds of genes simultaneously. Techniques like FISH help visualize chromosomal abnormalities directly within tissue, while gene expression profiling can provide insight into tumor behavior and potential treatment response.

Molecular diagnostics plays a central role in precision medicine by helping guide targeted therapies (e.g., identifying actionable mutations in tumors), predicting prognosis, monitoring minimal residual disease, and detecting emerging resistance mechanisms. Integrated with histopathology and clinical data, these tests enable more personalized, accurate, and effective patient care.