Flow cytometry is a highly sensitive technology for single cell fluorescent signals measurements. By using specific fluorescent probes, this technology allows simultaneous multiparametric analysis of many thousands of cells per second, enabling researchers to rapidly analyze complex cell populations. Cells or particles labeled with fluorescent molecules enter a fluid stream and flow at a constant speed in flow cytometer. When the cells pass through laser focuses along the stream one by one, the fluorescent probes are excited by the laser of specific wavelength and then emit light. The optics collects and transduces fluorescent light to the detector according to its color. Then the fluorescent light is detected, amplified and translated into an electronic signal, which will be processed by signal electronics and sent to a computer for presentation. Information about the cell is recorded and the result can be visually displayed on the computer screen in real time.
Flow cytometry-Cell Sorting(流式細胞分選)
Cell sorting is the physical isolation and enrichment of selected cells. Sorting on a flow cytometer is executed just after the standard measuring process. During sorting process the stream is controllably vibrated at a specific frequency to stably break it into droplets. These droplets containing cells with selected values by investigator are then positively or negatively charged more or less and go through a constant electric field. As a result the charged droplets are sent along selected trajectories into vessels (tube or plate), and the uncharged fluid containing non-target cells flow into waste drawer.
When should you use flow cytometric cell sorting?(什麽時候可以使用流式細胞分選?)
1). To enrich target cell population at a very high purity of 95%-100%. 2). To sort desired cells on the basis of multiple parameter measurements. 3). To separate cell populations with some low expression antigens on cell surface. 4). To isolate cells according to the accurately quantitative density of specific cell markers. 5). To acquire one single cell in multi-well plates. 6). To separate cells on the basis of internal constituents or functional staining, e.g. fluorescent hydrolysates. 7). To detect and sort very rare cells (0.001% or less) from mixed populations.