Real immune cells are short-lived outside of bodies. To do the type of experiments they wanted, the researchers needed cells that can stay alive more than a couple of hours, have the ability grow and represent a relevant model of human immune cells. They obtained "immortalized mouse immune cells" from a collaborator at UCSF that have the needed life span, and are accepted as a model system by the immunology research community.
"We're starting with robust and well-characterized cells, which really simplifies development of our new technologies and methods," Singh says. "We'll soon be working with other cell types, though, like white blood cells directly isolated from human patients. Our approach is designed to be flexible enough to handle many different cell types, and it also minimizes the number of cells needed for analysis, so it should enable us to do some unique studies on rare cell types."
Proteins in the cells of interest are tagged with fluorescent molecules, essentially colored dyes. The dyes range from green to red and give researchers the opportunity to track proteins and see, for example, the dynamic cellular production of proteins or protein-binding processes inside or on the surface of the cells.
The team is developing one platform with two complementary microfluidic modules -- one for trapping and imaging viable cells during stimulation with pathogens. The other combines cell preparation steps, cell selection and sorting followed by analysis of protein content in the selected cell subpopulations.
"In effect, we are taking many work-horse technologies such as confocal microscopy, flow cytometry and immunoassays and combining them into one compact, miniaturized platform using our unique microfluidic and imaging tools," Singh says.
Hyperspectral fluorescence imaging wi
Source:DOE/Sandia National Laboratories