||Increasing Sensitivity of the Ortho Analytical Cytofluorograph by Modifying the Fluid System.
Zucker, R. M. ;
Elstein, K. H. ;
Gershey, E. L. ;
Massaro, E. J. ;
||Health Effects Research Lab., Research Triangle Park, NC. Developmental Toxicology Div. ;NSI Technology Services Corp., Research Triangle Park, NC. ;Rockefeller Univ., New York.
Flow cytometry ;
Fluorescence spectrometry ;
Signal-to-noise ratio ;
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By adding Teflon tubing of varying lengths and inner diameters to the effluent line of the Ortho 50H analytical cytofluorograph, the authors were able to triple the sensitivity of fluorescence and scatter detection without compromising resolution. By increasing sheath backpressure, the additional tubing increases particle residence time within the detection area and thereby increases the total photon emission density per particle. The resulting increase in sensitivity is desirable in applications requiring detection of particles exhibiting low-level fluorescence. The effect of the altered hydrodynamics on resolution is also discussed.