Figure 1.

CTC counts for individual patients did not change when measured at two time points. Blood from 3 patients with advanced cancer was assayed and analyzed. ADC samples were tested twice, on the day of first blood draw and either on day 1 or day 3 subsequent to the first blood draw. SCC samples were tested twice, once on the day of first blood draw and again on day 1 subsequent to first blood draw. All blood samples were divided into two subsamples and processed individually. The light grey and dark grey bars are presented as the CTC number from 2 independent 5-ml blood samples. CTCs were counted by immunofluorescence following staining with DAPI, an anti-human protein tyrosine phosphatase, receptor type C mAb and an anti-human epithelial cell adhesion molecule mAb. CTC, circulating tumor cell; ADC, adenocarcinoma; SCC, squamous cell carcinoma; mAb, monoclonal antibody.