Fluorescence in situ hybridization (FISH) has long been used to detect specific nucleic acid sequences in paraffin-embedded tissue sections. However, using fluorescent detection requires specialized training and expensive fluorescence microscopes. Zymed Laboratories Inc. of San Francisco has introduced the SP•T-Light™ line of chromogenic ISH (CISH) products based on its proprietary Subtractive Probe Technology (SPT™). These products provide researchers with probes and detection kits for CISH procedures, allowing markers to be visualized with a bright field microscope. According to John Bliss, director of marketing at Zymed, this technology will make ISH more accessible to cancer researchers and diagnostics laboratories.
CISH detection of HER2 gene in human breast cancer tissue using Zymed's SP*T-Light HER2 probe Although the small oligonucleotide probes used in most ISH applications provide specificity, the signals they generate are difficult to detect by any means besides fluorescence, a method that obscures surrounding tissue morphology. Using longer, more highly labeled ...