Table 3. Comparison of the three detection techniques.

Assay	Blood volume per test	Principle of CTC enrichment	Method of detection
CellSearch	7.5 ml	Immunomagnetic – EpCAM	Visual confirmation of fluorescently labeled cells (CK+/DAPI+/CD45−)
AdnaTest	2 × 5 ml	Immunomagnetic – 2 anti-Muc-1 Ab and 1 anti-EpCAM Ab	Multiplex RT–PCR for HER2, Muc-1 and EpCAM
CK-19/MAM RT–PCR	9 ml	Size filtration of PB mononuclear cells	Multiplex real-time quantitative RT–PCR for CK-19 and mammaglobin

Abbreviations: CTC=circulating tumour cell; RT–PCR=reverse transcription–PCR.