The BMG LABTECH PHERAstar and POLARstar Omega plate readers are superbly designed instruments with a shared, simple user interface and robust capabilities. I have been using the PHERAstar for the last 2 years and the POLARstar Omega extensively over the last 8 months.
PHERAstar: The PHERAstar is a versatile plate reader for 96-well, 384-well, and 1536-well kinetic and endpoint applications. It is a module-based microplate reader designed for fluorescence intensity, fluorescence resonance energy transfer (FRET), fluorescence polarization (FP) (fluorescein and FarRed), Time-Resolved Fluorescence, Time-resolved FRET and AlphaScreen. The optical components for each application are neatly packaged in a bar-coded black metal case that is stored in the PHERAstar (five modules at a time). Custom modules can be ordered from BMG LABTECH if you have an application that uses non-standard dyes. Having used several plate readers for FP and FRET measurements, I have found the PHEARstar to be the easiest machine to get up and running, and I have been amazed by the quality of data obtained from all wells on a plate including edges.
POLARstar Omega: My lab has been using the POLARstar Omega for CFP/YFP-FRET, Intrinsic Tryptophan fluorescence assays, fluorescence polarization assays using non-FITC dyes, luciferase assays, and ELISA assays. The POLARstar Omega relies on two 8-slot filter wheels for emission and excitation filters. This allows the user to identify the optimal filter sets for a particular experiment and to easily “tweak” the setting to get the best results. If you need additional filters, it is very easy to change the filters, although the user must be careful to make sure the actual filters are synchronized with the filters that the software believes are in place. The only other inconvenience with using the POLARstar Omega is that you must change the optical unit for each application. For instance, if you want to perform FP and then switch to FRET, you must manually remove the FP optics and insert the FRET optics; however, this minor inconvenience results in high level of sensitivity over a wide range of applications. Additionally, I was pleasantly surprised to discover that the machine “knows” which optics are in place as well as the capabilities of that optic module. This prevents the user from the frustration of collecting FP data with the FRET optics in place.
Perhaps the most unique feature about the POLARstar Omega is its ability to measure the UV/Vis absorbance spectrum of a 96-well plate in a very rapid manner, although it should be noted that 96-well plates that do not interfere with UV absorbance are expensive. While injectors do not come standard with the POLARstar Omega, I highly recommend adding the injector system to this plate reader. This add-on has allowed our lab to monitor binding kinetics, determine initial enzymatic rates, and determine the kinetics of conformation changes in proteins.
Software: The software interface for the PHERAstar, POLARstar Omega and all other BMG LABTECH plate readers is identical, thereby allowing users to easily migrate from plate reader to plate reader without a learning curve. The user interface is well-designed with intuitive icons to allow a new user to get up and running with minimal training. In addition, there are myriad features that the advanced user can harness to simplify data analysis. The raw data can be exported easily to Excel if you so choose, but the software has a variety of features that make routine data analysis a breeze.
MD/PhD Candidate
Department of Pharmacology
University of North Carolina, Chapel Hill