Flow cytometry is used to analyze populations of cells or particles to detect and measure physical and chemical characteristics.
A sample of cells or particles is suspended in a fluid and inserted into a fluidic system via injection. Fluidic systems can vary greatly but mostly it reduces the bulk sample into a flow of a single stream of particles. This flow is routed into a single column, typically with a cuvette, to pass in front of a focused laser beam where light is scattered based on the characteristics of the individual cells. In many applications, the sample is labeled with a fluorescent marker which absorbs the excitation light and emits a fluorescent signal at a different wavelength. This process allows thousands of cells, and even different cell types, to be quickly analyzed and produce data which can be processed to diagnose diseases, contaminations, and many other helpful information in Life Science.
Flow Cytometry can be used for research, clinical diagnosis, and clinical trials such as drug efficacy. There are many uses for flow cytometry such as:
- Cell Counting
- Cell sorting
- Disease diagnosis
- Detecting various microorganisms
- Biomarker detection
- Apoptosis
- Cell Cycle Analysis
- Cell Proliferation Assays
- Immunophenotyping
- Intracellular Calcium Flux
Flow Cytometers are very useful in analyzing many cells in a sample. Unlike a microscope, that only gives an image of a single cell or small sample, a flow cytometer can give high-throughput, automated quantification of specified optical parameters on a cell-by-cell basis.
Flow cytometers have several common components regardless of type. A flow cell (often times called a cuvette), a measuring system, a detector, an amplification system and a computer to analyze the data. The flow cell can either be the type with a sheath to center the sample in the flow channel, or without a sheath giving a wider area for the sample. The measurement system is either via impedance or optical systems. In optical systems, a laser beam is focused through various optics to manipulate the beam into the correct width and height. This beam is then propagated through the flow cell and illuminates the sample. The resulting scattering of light and possible fluorescence signal are detected through precisely positioned detectors. The resulting detection signal is then converted to digital outputs and analyzed to produce CV data plots such as these:
This is where Vortran Laser’s understanding of flow cytometry can help. Our Stradus® family of lasers are very stable and low noise with excellent beam positioning. This helps in flow cytometer systems by not adding additional variation to the excitation beam causing false detections in the data. Our Stradus Lite laser in particular is a lower cost but still high-performance laser with particular specifications that lends itself to OEM instrument production. The robust design and simplicity of the laser is what helped lead William Telford to integrate this laser into his traveling and teaching cytometer (CytometryWorks). It has continued to perform extremely well even with the thousands of miles traveled and multiple setups and breakdowns. The higher-level light source system is our Stradus VersaLase systems which are a multi-wavelength combined laser system that can either be free space or fiber coupled. This allows the user to take advantage of a single interface to control multiple laser outputs for complex multi-color assays.
