Detection Method of Circulating Tumor Cells and Pretreatment Method for Detecting Circulating Tumor Cells

A method for detecting circulating tumor cells in a blood sample, comprising steps of:

• (a) filtering a blood sample through a filter to capture cells on the filter;
• (b) contacting with the cell-captured filter,
• a primary antibody that recognizes a leukocyte marker protein, and subsequently a secondary antibody that recognizes the primary antibody and is labeled with a first fluorescent dye, or
• an antibody that recognizes a leukocyte marker protein and is labeled with a first fluorescent dye;
• (c) contacting
• (c1) an animal serum,
• (c2) a surfactant and
• (c3) an antibody that recognizes an epithelial cell marker protein and is labeled with a second fluorescent dye
• with the cell-captured filter simultaneously or in any order;
• (d) contacting a third fluorescent dye that stains nucleic acids with the cell-captured filter;
• and
• (e) irradiating the cell-captured filter with respective excitation lights of the first, second and third fluorescent dyes to detect respective fluorescences of the first, second and third fluorescent dyes emitted from each cell captured on the filter,
• wherein step (d) is performed at any stage between step (a) and step (e).