In Situ Hybridisation

In Situ Hybridisation designates a molecular technique detecting specific nucleic acid sequences within intact cells, tissue sections, or whole organisms through complementary probe binding followed by visualisation, enabling spatial localisation of RNA or DNA targets maintaining tissue architecture and cellular context. Fluorescence in situ hybridisation (FISH) represents the most common variant.

The biopharmaceutical industry employs in situ hybridisation across research, development, and diagnostics. Cancer diagnostics employ FISH detecting chromosomal abnormalities including gene amplifications, deletions, or translocations guiding treatment selection or prognosis. HER2 FISH testing determines eligibility for trastuzumab therapy in breast cancer, while ALK rearrangement detection identifies lung cancer patients benefiting from targeted therapies. Clinical trial correlative studies use ISH examining target expression or treatment-induced changes in biopsy samples. As spatial transcriptomics advances enabling genome-wide in situ profiling, ISH continues providing essential insights into gene expression patterns and disease mechanisms.