Cell analysis system based on immunomagnetic cell selection and alignment followed by immunofluorescent analysis using compact disk technologies

Background: Although the flow cytometer has become the standard in cell ana lysis, it has limitations. Recently, we introduced a new cell analysis meth od based on immunomagnetic selection and aligning of cells. No now system i s needed and cell analysis can be pet-formed in whole blood. Methods: Whole brood is incubated with fluorescent labels and immunomagneti c nanoparticles. The blood is injected into a capillary that is in a strong magnetic field. The immunomagnetic-labeled cells move upward and align the mselves along ferromagnetic lines present on the upper surface of the capil lary. An optical focus and tracking system analogous to that used in a conv entional compact disk player focuses a 635-nm laser-diode on the magnetical ly aligned cells. The emitted fluorescence signals are projected on two pho tomultipliers. Allophycocyanin (APC)-labeled CD4 (CD4-APC) and Cyanin5.5 (C y5.5)-labeled CD8 (CD8-Cy5.5) antibodies and Oxazine750, all red excited, a re used as fluorescent labels. Results: A differential white blood cell count performed in whole blood is obtained using the CD4-APC in combination with Oxazine750. The results are compared with the Technicon-H1 hematology analyzer. Correlation coefficient s of 0.91 for neutrophilic granulocytes, 0.93 for lymphocytes, 0.93 for mon ocytes, and 0.96 for eosinophilic granulocytes were obtained. Immunofluores cence is demonstrated using CD4-APC and CD8-Cy5.5. The absolute counts obta ined for CD4+ and CD8+ are compared with the Coulter Epics XL flow cytomete r. Correlation coefficients of, respectively, 0.91 and 0.94 were obtained. Conclusion: We conclude that our system is as capable as a standard flow cy tometer or hematology analyzer for a reliable routine white blood cell anal ysis, including immunophenotyping, and can be used as an easy-to-handle dis posable white blood cell test. Cytometry 43:31-37, 2001. (C) 2001 Wiley-Lis s,Inc.