Microfluidic Cassette Analyses Genes and Proteins

A new method to isolate cells from patient samples is under development and analyzing them will help predict outcomes after severe trauma The technology, called a microfluidic cassette, allows precise analysis of very small volumes of fluids and can be used to study patients' genes and proteins.

Knowing the genomic signature of a cell population can help doctors diagnose diseases and may allow them to predict how individual patients will respond to trauma and what treatments to order. The approach also could be used with patients who have cancer or other conditions. Scientists at the University of Florida, (UF; Gainesville, FL, USA), developed and tested the cassette to isolate neutrophils, the first type of white blood cell on the scene of an infection, and to analyze the proteins they produce. A sample of fluid, such as blood or urine, is pumped through the device, which is laced with antibodies that capture the individual cells.

Testing showed the device yielded pure samples of neutrophils, and their gene expression pattern was consistent with results from tests performed in previous studies. The team was able to identify 63 genes that are differentially expressed. The genes in question regulate functions of the immune system. Patients, whose expression of these genes is abnormal, are less likely to return to their normal immune function within days of trauma, as most patients do. This leaves them more vulnerable to infections and a myriad of related complications.

Lyle L. Moldawer, Ph.D., a professor at UF said, "What is so powerful about this technique is that you can isolate any cell population quickly and efficiently at the bedside. In this case we isolated blood neutrophils, but we' have also isolated T cells, mixed leukocytes, monocytes. Theoretically, you can isolate any cell population, under any disease, and rapidly get nucleic acids to produce a genomic signature."

Kenneth Kotz, Ph.D., a research fellow at Massachusetts General Hospital (Boston, MA, USA) added, "We are getting 100 ng of ribonucleic acid (RNA) from 0.15 mL of blood and we're doing it all in 30 minutes. No one has really ever been able to do this for neutrophils. No one has been able to demonstrate the speed and the sample quality with these small blood volumes." The results of the study were published September 2010 in Nature Medicine.

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University of Florida
Massachusetts General Hospital