Download the full protocol and application data by completing the form to the right. 


Looking beyond EpCAM... 

Using the IsoFlux System with antibody cocktails to enhance CTC capture

Immunomagnetic cell separation in the IsoFlux System is based on the binding of magnetic particles to surface antigens that are present in CTCs but absent in surrounding leukocytes. The types and numbers of target cells recovered with the IsoFlux System will depend on the capture markers used. Certain markers, such as EpCAM, are generally understood to be present in most carcinomas (cancers of epithelial origin), but the expression of single markers can be heterogeneous in CTCs.  

Given the heterogeneity of the CTC population and likely variations between different cancer types, it is advantageous to be able to separate CTCs based on multiple surface markers. The ability to select the surface marker of interest can also aid in selecting specific CTC sub-populations.

The IsoFlux System enables the use of user-defined antibody cocktails to enhance CTC capture. This provides a means for capturing more CTCs, including ones undergoing epithelial to mesenchymal transition.  

In addition to CTCs, many other rare cell types of scientific and clinical interest can exist in the peripheral blood circulation. These include cancer stem cells, immune cells, and circulating endothelial cells. In many cases, these cells can also be enriched from the background cells using one or more surface-expressed antigens.


 

Recovery using individual antibodies and cocktails. The CTC beads (pre-conjugated with EpCAM), IgG Beads with EpCAM, and IgG beads with EGFR all displayed recovery of BT549 cells in the 45-50% range when used alone. The antibody cocktail using EGFR + EpCAM + HER2 increased the total recovery to 76%.

Recovery using individual antibodies and cocktails. The CTC beads (pre-conjugated with EpCAM), IgG Beads with EpCAM, and IgG beads with EGFR all displayed recovery of BT549 cells in the 45-50% range when used alone. The antibody cocktail using EGFR + EpCAM + HER2 increased the total recovery to 76%.

Immunofluorescence data for different model cell lines. We confirmed  protein expression profiles via immunofluorescence imaging for three different cell lines.  While SKBR3 is a very high EpCAM expressor, both MDA-MB-231 and BT549 exhibit no visible EpCAM expression and medium EGFR expression. These low EpCAM cell lines were used to validate an antibody cocktail that includes EpCAM, EGFR, and HER2.

Immunofluorescence data for different model cell lines. We confirmed  protein expression profiles via immunofluorescence imaging for three different cell lines.  While SKBR3 is a very high EpCAM expressor, both MDA-MB-231 and BT549 exhibit no visible EpCAM expression and medium EGFR expression. These low EpCAM cell lines were used to validate an antibody cocktail that includes EpCAM, EGFR, and HER2.