Flow cytometers are becoming the instrument of choice in a growing number of applications, including marine biology, cancer biology, drug screening, cell-cycle analysis, intracellular analysis, rare event detection, immunophenotyping, and stem cell research. Increasingly firms are developing benchtop systems that can be operated with minimal training while delivering enhanced capabilities, which further increase their utility.
Flow cytometry gathers data not only on cell numbers, but also on such cellular parameters as size, complexity, phenotype, health, and functionality. It has also entered the clinical laboratory for diagnostics and determining patient response to drug regimen. “Flow cytometry is a fundamentally powerful tool,” emphasizes J. Clark Mason, senior director for global marketing for BD Biosciences.
“Getting a more granular perspective of what’s going on in cells is a key driver,” in the growth of flow cytometry applications, according to Jason Whalley, market manager for flow cytometry at EMD Millipore. Ascertaining cause and effect of various actions, not just on a single cell but upon entire populations, relates directly to systems biology and therefore, increases the potential utility of flow cytometry.
“Combining immune phenotyping with the molecular world is the major topic we are working on,” according to Wolfgang Mann, Ph.D., group manager for the single-cell product line at Beckman Coulter. “It’s a very new idea.”
Dr. Mann is using flow cytometry to detect and characterize circulating tumor cells in the bloodstream. “Circulating tumor cells are a rare species of cells. They are present at a rate of a few cells per milliliter. The problem is to pick the few cells that can be expressed in human phenotyping, so you need a high-speed method to screen the cells and find the rare ones. Flow cytometry is the method of choice to isolate them.
“The challenge of isolating rare cells could be applied to other fields,” Dr. Mann insists, suggesting stem cell analysis, as stem cells seem to be related to tumor cells and tumorigenesis. Another application could be the analysis of fetal cells circulating in material blood. “If you want to study cell populations, like human B cells or other homogenous cell populations, one should use a flow sorter, like the Astrios, to prepare these cells, in high quality, for molecular analysis.
“In the past, there was a gap between flow cytometers expertise and people working in genetics. This gap is being closed.”
“Many applications have been around a long time, but were not fully exploited because of the complexity of flow cytometry systems,” says William Gutierrez, director of marketing for Blue Ocean Biomedical, which recently received ISO 13485: 2003 manufacturing certification, paving the way for commercialization of its load & go™ flow cytometers. “Flow cytometry manufacturers generally haven’t taken the lead in integrating and automating the applications. They leave it to customers,” resulting in assays that aren’t standardized. “We hope to be a catalyst in that area.
“Our objective is to take repetitive testing in both research and clinical environments and offer fully automated solutions to the user.” Blue Ocean’s first assay is a lymphocyte subset panel assay for immune monitoring, and assays are in development for stem cell counting for bone marrow transplants, leukocyte counting for blood banks, and patient transplant monitoring. A hematology test kit to reduce the need for WBC differentials is also being developed.
“We’re working with our customers to develop and simplify assays, and to customize some of theirs. The CR Tools package lets Blue Ocean work with customers to create custom load & go assays.”