Cytometry is a bioanalytical tool in which single or multiple cellular properties are determined by analyzing large populations of cells. The fluorescence labelled cells normally pass through the laser beam in a hydro-dynamically focused jet stream in a flow cell. Alternatively they are distributed on a plate and scanned by the laser beam. More advanced systems can be used for Fluorescence-Activated Cell Sorting (FACS). Cytometry instruments are often used as diagnostics tools and main applications include hematology, clinical chemistry and immunology.

High power, excellent beam quality and low noise are important properties of the laser source in order to maximize resolution and sensitivity (often referred to in terms of a low CV value) of the instruments, and for applications with high throughput requirements.

Confocal microscopy allows incredibly thin regions of cells or organisms to be easily and clearly visualised by discriminating out of focus light using pinholes. This microscopy method facilitates the investigation of cell dynamics, in particular of live cells, on a very high resolution scale.

Lasers are used in confocal microscopy to excite fluorophores and reagents which are attached to the cell or organism under investigation. The laser light is scanned across the sample in a confocal configuration and the fluorescence is detected through a confocal pinhole, which gives very high resolution. Alternatively, the laser light passes through rotating (spinning) disks of pinholes. In recent instruments the laser can also be scanned across the sample as a line, which enables very high frame rates, but requires higher power lasers.

Other applications related to this field are TIRF (total internal reflection fluorescence), FRAP (fluorescence recovery after photo bleaching) and FCS (fluorescence correlation spectroscopy).

The wavelength flexibility, low noise, and high power make the Cobolt lasers suitable as excitation sources in most fluorescence microscopy applications. The Cobolt Calypso at 491 nm has proven to match very well the traditional Ar-ion line at 488 nm and the Cobolt Jive at 561 nm makes a very good replacement for the Kr-ion line at 568 nm. In addition, the multi-line Cobolt Dual Calypso is particularly attractive for fluorophore multiplexing applications. DPSS lasers are now also interesting as a high power excitation source, to replace arc lamps, for wide-field microscopy.

This group of analysis tools include different types of plate or chip readers as well as instruments based on capillary electrophoresis technology. These tools are mainly used for studies of genes (location, interaction, structure, and function). Main applications are High-Though-put Screening (HTPS) processes for new drug development and DNA sequencing. One specific aim in this segment is the development of biochip technology, with the ultimate goal to enable tailored medical treatment based on the patient’s genetical response.

Wavelength matching (with Ar-ion lasers), beam quality and low noise are important properties of the laser source.