Fluorescence correlation spectroscopy (FCS) is a relatively new subsegment of the fluorescence spectroscopy market designed for advanced research. FCS can provide very specific physiochemical information that is most useful in biology and related sectors. Technical advancements in recent decades have allowed the technique to be developed as a commercial instrument technique that is still in the early-market phases.

FCS measures the fluctuation of fluorescence of very small particles and molecules and can provide the concentration and size of the particles or molecules being analyzed. It is an extremely sensitive technique that measures a very small volumetric space (femtoliters) and can provide a wealth of information, such as nanomolar concentrations. In most cases, FCS systems integrate both a detector and a microscope to provide imaging capabilities. In some cases, FCS systems are sold as an integrated system. In other cases, they are sold as detectors that are designed to be paired with an existing laser or confocal scanning microscope. Configurations and system prices vary widely, largely depending on the number and types of lasers used.

FCS is heavily oriented toward basic and applied research applications. It can help to determine properties such as diffusion coefficients, average concentrations, reaction rates and a host of other physiochemical properties. FCS is useful for observing fluorescent molecules in living cells, which makes it attractive for drug discovery and development. One of the biggest strengths of the technique is characterizing the mobility-related parameters of molecules. FCS can provide information on the interaction of therapeutic molecules and other important compounds with proteins and nucleic acids, while few other analytical techniques are capable. Because the technology is still so new, and extremely advanced, demand is largely centered around academic institutions performing basic research. Many scientists who may be able to benefit from the technique are as yet unfamiliar with it because it is not yet well known or developed.

The first major work in developing FCS took place in the 1970s. Early systems were not commercially viable as they were extremely complex to operate. Technological improvements and new measurement techniques that came about in the mid-1990s allowed for the development of powerful instruments for end-users. Since 2006, there have been about a half dozen new FCS instrument introductions.

The annual worldwide market for FCS is still less than $5 million, but it should have strong double-digit growth over the next several years as it becomes a more widely accepted analytical technique and more competitors enter the segment. Carl Zeiss is the leading vendor in the market, currently offering three models, which complement its microscopy business. The other vendors involved in the market are small firms and were mostly started in the 1980s or later.

Fluorescence Correlation

Spectroscopy at a Glance:

Leading Suppliers

• Carl Zeiss

• ISS

• Sensor Technologies

Largest Markets

• Academia

• Biotechnology

• Pharmaceuticals

Instrument Cost

• $100,000–$500,000