Patent ID: 7527978

Claim:
A method for analyzing immature reticulocytes for the presence of micronuclei comprising the steps of: a) immuno-magnetically isolating reticulocytes from a human blood cell sample by contacting the sample with first reticulocyte surface protein—selective first antibody coated, flow cytometry-compatible magnetic beads, under conditions wherein the first antibody selectively binds the reticulocytes, applying a magnetic field to the sample to magnetically segregate antibody-bound reticulocytes, and washing away unsegregated material; b) labeling magnetic bead-bound reticulocytes of step a) with a fluorescently labeled second reticulocyte surface protein—selective second antibody; c) permeabilizing the magnetic bead-bound reticulocytes of step b) to an RNase and a DNA-staining fluorescent dye, and then treating the reticulocytes with the RNase to prevent RNA-staining from interfering with analysis of the micronuclei and staining micronuclei of the reticulocytes with the DNA-staining fluorescent dye, wherein the dye and the fluorescently-labeled second antibody have overlapping absorption spectra, and distinguishable emission spectra; and d) analyzing the labeled magnetic bead-bound reticulocytes of step c) for the presence of stained micronuclei using single-laser flow cytometry; wherein the first and second reticulocyte surface proteins are independently selected from the group consisting of transferrin receptor (CD71), glycophorin A (CD235a), thrombospondin (TSP) receptor (glycoprotein IV; CD36), and integrin α4β1(very late activation antigen-4(VLA- 4 ), and CD49d/CD29).