Product
Review
Going with the Flow
The gap between benchtop and floormodel flow cytometers narrows.
In recent years, the differences between benchtop flow cytometers and the larger, more versatile highperformance sorting instruments have decreased. Most notably, the traditional dividing jjne floor-model instruments can analyze and sort particles whereas benchtop instruments limited to analysis has been breached. In addition, the inclusion of more features on the benchtop instruments and improvements in the sensitivity of floor-model instruments have helped narrow the gap. t\±v n u w \~y IL/IIICICI s u s e c i c c u uupuccu
teciimquco LU analyze particles in a continuously iiowing stream. Aiinough particles Elizabeth Zubritsky
from multicellular spheroids to DNA fragments can be studied, researchers typically focus on analyzing and sorting cells. Popular applications include identifying malignant cells and monitoring immune-system cells; some flow cytometers have been designed specifically for these and other clinical applications. However, research-grade flow cytometers tend :o support a greater variety of techniques ind offer more flexibility and modularity. This Product Review will focus on research-oriented flow cytometers. To give •eaders an overview of these instruments Analytical Chemistry yalked wiih Laary Arlold of the University of North Carolinachapel Hill James Jett of Los Alamos Na-
tional Laboratory, and Todd Christian of the instrument manufacturer BD Biosciences. Arnold runs a flow cytometry core facility, and he is a consultant for the instrument manufacturer Cytomation and a former consultant for Coulter. Jett's lab has been a National Flow Cytometry and Sorting Research Resource, which is sponsored in part by the National Institutes of Health, for 18 years. Tables 1 and 2 list representative benchtop and floor-model instruments, respectively. These tables are not meant to be exhaustive but to provide a launching point for inquiries about flow cytometers. Interested readers should contact companies directly for additional information. To sort or not to sort? The main decision in buying a flow cytometer is whether to buy one that sorts particles in addition to analyzing them. Sorting the particles means selecting only a fraction of the total population and collecting them—perhaps in tubes or the individual wells of a microwell plate. These days, a
Analytical Chemistry News & Features, November 1, 1999 755 A
Product
Review
Table 1 . Representative benchtop flow cytometers.1 Product
EPICS XL
FACSCalibur
MoFlo BTS
PAS-III
Company
Beckman Coulter P.O. Box 169015 MC 195-10 Miami, FL33116 800-327-6531
BD Biosciences 2350 Qume Dr. San Jose, CA 95131 800-223-8226
Cytomation 4850 Innovation Dr. Fort Collins, CO 80525 800-822-9902
Partec Otto-Hahn-Str. 32 D-48161 Munster, Germany +49 2534 8008-0
URL
www.beckmancoulter.com
www.bdfacs.com
www.cytomation.com
www.partec.de
Dimensions (cm)
56 W x 61 D x 61 H
91.4 W x 61.5 D x 67.3 H
125 W x 76.25 D x 74 H
75 W x 61 D x 47 H
Number of lasers
1
1 is standard; 2nd laser optional
1 is standard; up to 3 available
1 is standard; up to 3 available
Optical parameters
3 or 4 fluorescence
Up to 4 fluorescence and 2 scatter
10 fluorescence and 2 scatter is standard; up to 16 fluorescence available
6 fluorescence and 2 scatter
Fluorescence sensitivity (MESF)
250 using FSCS particles
200 using Spherotech Rainbow particles
80,000 events/s; data rates up to 150,000 events/s
Designed for immunophenotyping, DNA analysis, and microbiology; true absolute counting does not require reference samples; setup in
