Yousef Nazirizadeh discusses the evolution of this valuable tool and asks what’s next for microplate readers
Introduced in the 1970s, the first microplate readers were designed to read absorbance in 96-well format, with their first major application being the enzyme linked immunosorbent assay (ELISA). Since then, technological advancements have allowed for more sophisticated methods and usage. Essentially two technological developments have bolstered this progress: the adoption of LED technology and elimination of scanning mechanics. Microplate readers implementing both LEDs and a scan-free readout are referred to as solid-state readers (SSR). These readers are characterised by their unique features and offer new possibilities in terms of laboratory decentralisation.
SSRs providing a technological shift
Over the years, the technology of various light sources has evolved to offer increasingly advanced options, such as halogen, tungsten, deuterium, and Xenon flash lamps, as well as LEDs. In the case of SSRs, LEDs are the preferred choice. Not only do they offer increased longevity – 20,000 hours before loss of intensity – they also deliver a drastic increase in energy efficiency. Compared with a typical halogen lamp, LEDs are more than 85% more efficient. LEDs can also be tailored to discrete wavelengths, making them even more energy efficient.
Scanning mechanisms found in traditional microplate readers were required to bring the wells of a microplate under the detection units. These mechanisms are also used for shaking the plate. However, by definition, SSRs completely forego any moving parts or scanning mechanisms. This is accomplished by using a multiplexed electronic that allows each of the 96 wells of a microplate to have a dedicated light source and detector.
What are the key features of a solid-state reader?
Due to the absence of mechanical parts and motors, SSRs are highly compact devices. Using the example of the Absorbance 96 from Byonoy, the footprint of such a reader is scarcely larger than the microplate itself. This drastic size reduction enables a more flexible use compared with traditional readers, as it is not restricted to a specific location due to its size or weight.
As a result of the reduced power requirements of operation and high-efficiency LED technology, SSRs can also be powered using a single USB cable and do not require an outlet – just a laptop or tablet to run the software.
Due to the simplicity of these readers, installation and maintenance requirements are also essentially eliminated. No service or installation by a technician is necessary. SSR devices are also self calibrating, preventing the need for extensive, costly, post-purchase calibration by the manufacturer.
These specific features also mean that SSRs are inherently portable devices. Wherever a laptop or tablet is available, a solid-state microplate reader can be used to establish decentralised testing facilities, thus easily increasing testing capacities and expanding existing laboratory infrastructure.
The singular importance of this type of flexibility is currently manifesting itself through the worldwide Covid-19 pandemic. The ability to increase testing capacities and to equip laboratory personnel with affordable, user-friendly devices with a low barrier to entry is essential in combatting the crisis.
SSRs redefining future labs
Over the past few decades since their inception, the gradual evolution of microplate readers has yielded little change. The SSR however, represents a revolutionary step toward a new, more flexible type of microplate reader that can support new applications, such as the establishment of decentralised laboratories for Covid-19 testing.
Yousef Nazirizadeh, PhD, is CEO of Byonoy