Figure 2
Comparison of tumor cell EpCAM and CK protein stability in BCTs and K 3 EDTA tubes. Blood was drawn into K3EDTA tubes and BCTs and plasma was isolated. MCF-7 cell were spiked into plasma and stored at RT. Cytospin samples were prepared at indicated time points and expressions of EpCAM and CK proteins were determined using the standard immunofluorescence cell staining protocol as described in the “Materials and Methods” section. Tumor cell proteins, EpCAM and CK, cell nucleus and nuclear content were stable in BCTs at RT for 4 days. However, tumor cells incubated in K3EDTA plasma showed degrading EpCAM and CK proteins, nucleus and nuclear content upon storage at RT for 4 days. Original magnification x 40. Representative staining results from 3 independent experiments.