How does the CELLSEARCH® System work?
The CELLSEARCH® System uses unique technology to capture, isolate, and enumerate circulating tumor cells (CTCs)
1 Magnetically separating CTCs from other cells
A 7.5-mL sample of blood is placed in a special tube, centrifuged to separate solid blood components from plasma, then placed in the CELLTRACKS® AUTOPREP® System. Using ferrofluid nanoparticles with antibodies that target epithelial cell adhesion molecules, CTCs are magnetically separated from the bulk of other cells in the blood.
2 Differentiating CTC cells
CTCs are then stained with cytokeratin monoclonal antibodies, which are specific to epithelial cells.
3 Identifying contaminating leukocytes
A monoclonal antibody stain is used to identify CD45—a marker specific to leukocytes—which identifies any leukocytes that may have contaminated the sample.
4 Highlighting cell nuclei
A DNA stain called DAPI is also added to highlight the nuclei of both CTCs and leukocytes.
5 Prepping cells for analysis
Cells are put in a magnet cartridge that applies a magnetic force that pulls the cells to a single focal depth.
6 Highlighting and enumerating CTC cells
The cartridge containing stained CTCs is placed onto the CELLTRACKS ANALYZER II® System for scanning. Once the cartridge has been scanned, the system displays tumor cell candidates that are positive for cytokeratin and DAPI. These candidate cells are presented to an operator for final review.