RosetteSep CTC Enrich w/ CD56, 10 mL

This immunodensity negative selection cocktail from STEMCELL Technologies enriches untouched, viable circulating epithelial tumor cells (CTCs) directly from human whole blood by depleting hematopoietic cells expressing CD3, CD14, CD16, CD19, CD38, CD45, CD56, CD61, and CD66b. The antibody cocktail crosslinks unwanted cells to multiple red blood cells (RBCs), forming immunorosettes that pellet with free RBCs during centrifugation over a density gradient medium, allowing desired CTCs to be collected as a highly enriched population at the plasma–density gradient interface. The enriched cells are immediately available for downstream applications such as flow cytometry, cell culture, or DNA/RNA extraction, and the product can also be used with buffy coat as a starting sample.

Supplied as a combination of monoclonal antibodies in PBS, the cocktail should be stored at 2–8°C without freezing. For optimal performance, whole peripheral blood should be used within 24 hours of collection and kept at room temperature (15–25°C). The nucleated cell concentration should not exceed 5 × 10⁷ cells/mL, with at least 100 RBCs per nucleated cell. The recommended density gradient medium has a density of 1.077 g/mL. For higher-throughput processing, the cocktail can be combined with SepMate™ tubes. Typical CD45+ cell depletion ranges from 3.2 to 4.4 log. The cocktail is recommended for the enrichment of CTCs from breast cancer samples, but is not suitable for small cell lung cancer (SCLC) or pancreatic carcinoma samples because CD56 has been shown to be expressed on these tumor types.