Apparatus and process for the detection and counting of rarely occurring mammalian cells

摘要

Apparatus and process capable of rapid detection and counting of rarely occuring mammalian cells in blood and other tissues which have been labeled with a fluorescent dye.;Said process comprises: scanning a solid support on which a sample potentially containing fluorescent cells has been deposited, with an incident beam from a laser, forming a laser spot on the solid support, said laser spot being substantially greater than the cells to be detected, said laser spot size being comprised between 15 and 30 µm; and simultaneously: detecting the resultant fluorescent light at least at one wavelength; establishing a set of correlated-features by a line-to-line correlation of individual features; comparing said correlated-features on each pair of adjacent lines in time synchrony, at least at two different wavelengths λ₁ and λ₂; making a size discrimination of retained events and selecting those having a size corresponding to the type of cells searched; determining if for retained events after size discrimination, the events energy profile in three dimensions is within predetermined Gaussian shape criteria; and counting said remaining events to determine and to count exclusively the fluorescent cells present on said solid support.