The CellSearch® Epithelial Cell Kit contains a ferrofluid-based capture reagent and immunofluorescent staining reagents. The ferrofluid reagent consists of nanoparticles with a magnetic core surrounded by a polymeric layer coated with antibodies targeting the Epithelial Cell Adhesion Molecule (EpCAM) antigen for capturing circulating tumor cells (CTCs). After immunomagnetic capture and enrichment, fluorescent staining reagents are added for identification and enumeration of CTCs. Anti-CKPE is specific for the intracellular protein cytokeratin (specific for epithelial cells), DAPI stains the cell nucleus, and anti-CD45-APC is specific for leukocytes.

When sample processing is complete, images are presented to the user in a gallery format for final cell classification. The user classifies an event as a tumor cell based on morphology and correct phenotype, i.e., EpCAM+, CK+, DAPI+ and CD45-.

The CellSearch® Epithelial Cell Control Kit contains single-use bottles of fixed cells from a breast carcinoma cell line (SK-BR-3). Each bottle contains a population of control cells. A CellSearch® Epithelial Cell Control bottle is substituted for a patient sample to verify the performance of the CellSearch® Epithelial Cell Kit reagents, sample processing by the CellTracks® AutoPrep® System, and cell analysis by the CellTracks® Analyzer II.

Each single use bottle in the CellSearch® Epithelial Cell Control Kit contains two populations of SK-BR-3 cells. The control cells are fully compatible with CellSearch® Epithelial Cell Kit reagents and are automatically identified as CTCs by the CellTracks® Analyzer II. The cells are differentiated as control cells by the detection of fluorescence in the control channel of the CellTracks® Analyzer II.