Performance evaluation of the FACSCount system: A dedicated system for clinical cellular analysis

Abstract

Flow cytometers are instruments that can determine multiparameter data simultaneously and have a great potential in providing unique information about cells. The FACSCount System is designed as the first dedicated flow cytometer for the clinical laboratory. Its current configuration provides CD4, CD8, and CD3 absolute counts from 100 μl of whole blood. Adapting the FACSCount System to the clinical setting are minimal sample handling, lysis free cell preparation, automated fluorescence gating, built‐in calibrated reference beads, and appropriate error code reporting. Quality control checks ensure that reported CD4 counts, important for clinical follow‐up and patient management, are accurate, precise, and reproducible across instruments over time. © 1996 Wiley‐Liss, Inc.

Cytofluorometric methods for assessing absolute numbers of cell subsets in blood

“…Most of these methods have already been evaluated in multicenter studies (86,87,90,116,117,135). Some analysis systems were marketed in the past and are briefly described here for historic purpose.…”

“…The first applicable no-lyse technology was developed for CD4 counting on the FACSCount instrument (116). Strangely, no further developments of such a promising and effective technique have occurred since that time.…”

Comparison of 5 Flow Cytometric Immunophenotyping Systems for Absolute CD4+ T-Lymphocyte Counts in HIV-1-Infected Patients Living in Resource-Limited Settings

“…It is, at present, the oldest and the only dedicated cytometer that has been extensively validated and widely used. 15 This system automatically counts the CD4 + and CD8 + T lymphocytes in a twin tube (or only CD4 + T lymphocytes in a single tube) containing a mixture of mAb reagents for CD4/CD3 and a known density of fluorescent microspheres. Unfortunately, the running cost of this SP bead-based method using FACSCount or other instruments using 3-color mAb reagents, combined with reference microspheres, remains relatively high and beyond the reach of most patients with HIV/AIDS in resource-limited settings.…”

An integrated microfluidic system for counting of CD4+/CD8+ T lymphocytes

“…Therefore, there is a great need for a fast and accurate diagnostic method for HIV infection. Briefly, there are several existing methods which can be used for identifying a HIV infection, including (1) a serological diagnosis approach such as western blotting (Guan 2007), enzyme-linked immunosorbent assay (ELISA, Robinson et al 1990) and an agglutination test (Monzon et al 1992) either to detect HIV p24, which is a core protein in the HIV particles, to measure anti-HIV antibodies, (2) a molecular diagnosis approach such as real-time polymerase chain reaction (RT PCR) to quantitatively measure the HIV viral load (Lewin et al 1999), and (3) a cell-based assay to measure CD4 absolute counts or the CD4/CD8 ratio quantified by using flow cytometry (Balakrishnan et al 2004;Dieye et al 2005;Strauss et al 1996). Western blotting, ELISA and an agglutination test could capture HIV surface proteins or anti-HIV antibodies, and therefore, they can be used for fast screening of a HIV infection.…”

“…T lymphocyte counts using flow cytometry every 3-6 months. Flow cytometer is a crucial instrument for detecting one type of lymphocyte from another by labeling different fluorescent antibody probes specific for CD4 and other cell surface markers and excited by laser (Balakrishnan et al 2004;Dieye et al 2005;Strauss et al 1996). However, several concerns regarding the use of a large-scale flow cytometer, including the relatively high cost and the relatively high consumption of blood samples and reagents, have made this instrument difficult to use in resource-limited settings.…”