Detection and characterization of micrometastatic cells with the embedded tumor cell calibrator technique – Normalized RT-PCR

Background: We present a new technique called embedded tumor cell calibrators (ETC) for tumor cell enumeration and gene expression analysis. Material and Methods: Bone marrow and blood samples from normal donors and patients with breast carcinoma were devided in at least one native probe and several matched calibrator probes. Calibrator probes were spiked with either 2, 4, 8 or 16 breast carcinoma cells (embedded tumor cell calibrators, ETC). Native and matched ETC samples were processed side by side under identical conditions through the following steps: a) immunomagnetic tumor cell enrichment with high affinit…