I just got to kick the tires on one of BioTek’s newest readers, the Synergy 2 Alpha. The Synergy 2 Alpha is one of the continuing line of Synergy multimode readers specifically designed to run Amplified Luminescent Proximity Homogeneous Assays such as AlphaScreen® and AlphaLISA® assays. These assays are referred to as homogeneous in that they do not require any wash steps to remove unbound materials. These assays use active donor and acceptor beads that have been coated with biological molecules. With excitation, a photosensitizer in the donor bead converts ambient oxygen to reactive singlet oxygen. The high concentration of the photosensitizer in the donor bead results in the generation of large numbers of singlet oxygen molecules and serves as a means for signal amplification. The singlet oxygen species reacts with thioxene compounds in the acceptor bead to generate a chemiluminescent signal that emits at 370 nm. The energy is immediately transferred to fluorophores contained in the same acceptor bead, effectively shifting the emission wavelength to 520-620 nm. Because singlet oxygen is unstable, it can only diffuse a distance of 200 nm before it decays. The distance limitation insures that in the absence of a specific biological interaction between the two beads the singlet oxygen produced by the donor bead will go undetected. Acceptor beads that are not within this distance will not emit light.
The Synergy 2 Alpha uses a continuous tungsten lamp and filter switching to provide coordinated excitatory illumination along with the time delay prior to signal determination necessary for low background. This allows the reader to perform conventional fluorescent determinations without additional optics. Typically, devices that have been designed to run AlphaScreen assays utilize a dedicated laser for excitatory light. Monochromatic lasers provide continuous light output, as well as wavelength specificity, both of which are necessary for the AlphaScreen assay, but are very expensive. While the Synergy 2 Alpha gives up a little speed against the pricier laser based instruments, it works well for 96 and 384-well formats and doesn’t lose any sensitivity. As you can see from this c-AMP concentration curve the reader provides a large assay window.
In my opinion (admittedly biased) Synergy 2 Alpha is a great option for a lab that needs a microplate reader that can read conventional fluorescent determinations, but also has a need for some AlphaScreen® and/or AlphaLISA® assays, but can’t afford or need a full blown HTS system. Do you currently use AlphaScreen technology? Have you contemplated using AlphaScreen or AlphaLISA assays but could not justify the cost of the reader? If so, check out this reader.