Microplate readers are essential tools for scientific research, used to support many different applications. However, they typically exhibit only a limited number of detection modes and are often restricted in terms of the wavelengths they can measure, meaning researchers may have to compromise when it comes to assay design. The new VANTAstar™ microplate reader from BMG LABTECH is a compact, multi-mode instrument that offers several advantages over other systems. These include the incorporation of three different detection technologies for maximum flexibility and optimal performance in any workflow, as well as a range of features to simplify experimental setup and provide more accurate results.
Designed for ease-of-use and assay flexibility, the VANTAstar™ can be equipped with detection modes ranging from UV/vis absorbance, fluorescence intensity, and luminescence, through to time-resolved fluorescence, time-resolved FRET, and fluorescence polarization. Unlike many conventional microplate readers that offer only filter-based detection, the VANTAstar™ is available with both snap-in optical filter sets and patented Linear Variable Filter (LVF) Monochromators™. LVFs are specialized filters that vary spectral properties over their length; their use in a monochromator system provides comparable wavelength flexibility to a conventional grating-based monochromator but with superior light transmission and sensitivity. These detection modes are further augmented by a spectrometer capable of delivering the fastest full UV/vis absorbance spectra available (220–1000 nm at resolutions selectable from 1–10 nm, in <1 second/well).
In addition to multiple detection modes, the VANTAstar™ features Enhanced Dynamic Range (EDR) technology. This simplifies detection setup by ensuring every plate is automatically read with a setting that provides the best sensitivity and signal-to-blank ratios, thereby eliminating the need for end users to adjust gain settings. EDR technology also grants a dynamic range spanning >8 concentration decades in a single measurement, allowing for detection of both bright and weak signals on the same plate without requiring sample dilution and significantly reducing the risk of detector saturation. Other defining features of the VANTAstar™ include luminescence cross-talk reduction, the Atmospheric Control Unit (ACU) with CO2 and O2 control for optimal cell culture conditions, and flexible injectors that can be used to precisely initiate or stop a kinetic or enzymatic reaction. The VANTAstar™ is also equipped with a multi-user software package that includes the MARS data analysis software and can be installed on as many computers as required without the need to purchase additional licenses.
The VANTAstar™ effectively performs all mainstream applications and, in many cases, improves on existing methods. For example, researchers reading absorbance can now use spectral detection to highlight the presence of contaminants in DNA/RNA samples or shifting peaks in enzymatic reactions, while those performing real-time cell-based assays can benefit from atmospheric control and more uniform incubation conditions for greater experimental accuracy. Where reagent injection is required, the reagent dispenser module with integrated heater and magnetic stirrer enables reagent mixing and dispensing at a specific temperature and allows injection timing, speed, and volume to be independently adjusted for each sample in up to 384-well plates. Moreover, through continuous collaboration with major reagent companies, BMG LABTECH ensures that protocols are developed and instrument settings enhanced, both for existing assays and the very latest kits.
Researchers often transfect cells with exogenous DNA encoding a target gene and a fluorescent reporter to study the regulation of gene and protein expression. During these types of experiments, the transfection efficiency is typically determined by counting the number of reporter-expressing cells using a fluorescence microscope, a time-consuming process that can be prone to operator error. To demonstrate the utility of the VANTAstar™ for performing these measurements, researchers seeded GFP+/mCherry+ HeLa cells mixed in various ratios to wild-type HeLa cells before calculating the corresponding (simulated) transfection efficiencies. The VANTAstar™ provided reliable detection of GFP+/mCherry+ HeLa cells down to ~600 cells/well in a 96-well plate, proving it to be a viable alternative to microscopy-based methods.
Pyruvate kinase over-expression has been implicated in cancer, making inhibition of pyruvate kinase activity a promising strategy for therapeutic intervention. To demonstrate the utility of the VANTAstar™ to analyze enzymatic reactions, real-time detection of fluorogenic substrate conversion was performed in the presence of increasing concentrations of a known pyruvate kinase inhibitor. The EDR feature was critical to the success of this study due to the strong increase in signal intensity over time, while the integrated MARS data analysis software streamlined evaluation by removing the need for data export or formatting.
High-throughput cell viability assays are widely used for compound toxicity screening and frequently rely on commercially available kits that provide absorbance, fluorescence, or luminescence readouts for measurement with a microplate reader. Using three popular cell viability kits—Vybrant® MTT (colorimetric), alamarBlue™ (colorimetric or fluorescent), and CellTiter-Glo® (luminescent)—for assessing cell health, researchers showed the VANTAstar™ to be compatible with a broad range of assay formats. Moreover, with the luminescent readout, the VANTAstar™ enabled detection of fewer than 10 cells/well.