One of the more interesting developments in molecular spectroscopy over the past 10 years has been the introduction of spectrometers designed for use with small samples, generally on the order of a microliter. The need for such devices stems primarily from life science researchers. Foremost among the applications that have been enabled by these instruments are the quantitation of DNA, RNA and proteins in solution. Other types of bioanalysis are also possible, and applications are expanding from basic research to laboratories processing clinical samples.

The underlying measurement technology is generally UV as well as, or, visible light spectroscopy (UV/Vis). A minority of microvolume spectrometers are configured for fluorescence measurements. One of the technical difficulties of microvolume spectroscopy is that with a small sample, the path length of the measurement is smaller. This can increase potential errors in measurement, since the path length must be known precisely. Standard UV/Vis instruments typically use a 1 cm path length. Some microvolume systems use path lengths a hundred times smaller, such that minute variations in path length are proportionally much greater.

Some systems allow users to pipette a single microliter directly onto an optical component, such as the detector. The light source is then brought in contact with the drop, forming a “column” of sample through which the measurement can be made, with the optomechanical system adjusting the path length precisely. Other systems use cuvettes designed specifically for these small volumes; in some cases, these microvolume cuvettes can be fitted to standard UV/Vis instruments. These aftermarket cuvettes also form an important segment of the microvolume spectroscopy market because they feed into the much larger installed base of general purpose instruments. However, many researchers only require microvolume measurements; consequently, dedicated microvolume instruments have proliferated rapidly over the past decade.

The total market demand for microvolume spectroscopy products in 2015 was approximately $150 million. Thermo Fisher Scientific is the leading vendor. This dominance stems from its 2007 acquisition of NanoDrop Technologies (see IBO 10/15/17), one of the earliest and most successful market entrants. Thermo Scientific released the NanoDrop One product late last year. The success of Shimadzu’s BioSpec-nano places it in the second position in the market. Biochrom (Harvard Bioscience) had long provided GE Healthcare with OEM systems, but as of January 2016, Biochrom became responsible for sales and support of these product lines, becoming the third largest vendor.

Other vendors include Analytik Jena, Biodrop, DeNovix, Jenway (Bibby), Implen and Trinean. Another market participant, HORIBA, is notable for addressing the fluorescence segment of the microvolume spectroscopy market.

Microvolume Spectroscopy at a Glance:

Leading Suppliers

• Thermo Fisher Scientific

• Shimadzu

• Biochrom (Harvard Bioscience)

Largest Markets

• Academia

• Biotechnology

• Hospital and Clinical

Instrument Cost

• $5,000–$18,000