Microplate readers are widely used in research, drug discovery, bioassay validation, QC, and manufacturing processes for the detection of biological, chemical, or physical processes in samples contained in microtiter plates. There are a wide variety of microplate readers on the market, offering different capabilities and functionalities.
A number of criteria need to be considered before purchasing a microplate reader in order to ensure that the instrument chosen is appropriate for its intended purpose. When purchasing a microplate reader, the first consideration should be whether the reader will be needed to perform only one type of assay, or whether it will be required for multiple assays. If only one type of assay needs to be performed, a singlemode detection instrument should be purchased. However, if performing a variety of different assays is required, a multi-mode instrument should be purchased.
HTStec (Cambridge, UK) estimates market growth of microplate readers at about six percent per year, with an average high-throughput system costing between $65,000 and $110,000. Large pharmaceutical and biotech companies purchased 23 percent of systems, academic labs 25 percent, and small pharma/ biotech companies purchased 52 percent.
Microplate reader detection modes define the instrument’s experimental capabilities, while the optics determine spectral selectivity. Detection modes include top- and bottom-read fluorescence, fluorescence polarization, time-resolved fluorescence (TRF), time-resolved fluorescence energy transfer (TRFRET), AlphaScreen, absorbance, and luminescence. Absorbance and fluorescence intensity are the most widely used detection techniques, constituting more than half of all applications.
|Time-resolved fluorescence (TRF)||62%|
|Time-resolved fluorescence energy transfer (TR-FRET)||83%|
Labs have added components to their microplate instruments that are designed to perform specific functions, such as plate piercing, sealing, barcoding, and centrifugation. The top two components used in the labs of the respondents are centrifugation and microplate washers. Centrifugation is used for filtration purposes, air bubble removal in high density microplates, celluar debris, and spin downs. Microplate washers, on the other hand, are used to remove reagents from sample wells on microplates and to prepare them for the next step in an assay or procedure. Barcode scanners, the fourth most popular component, are used to recognize the code on the source microplate; along with barcode scanners, labs are purchasing labeling and sealing equipment.
|Additional stacker cassettes||11%|
|Labeling and sealing||7%|
|De-lidding stacker cassettes||4%|
Respondents identify flexibility (available detection modes), performance (sensitivity, throughput), and cost as prime considerations in microplate readers’ selection. However, the order of preference may differ for each market; for example, pharmaceutical screeners typically value throughput as their top criterion, while academic researchers may be more satisfied with a lower throughput but high flexibility, particularly if it means a lower overall cost. Other desirable features include a full complement of detection modes, sample throughput, advanced optics, additional photomultiplier tubes for reading two wavelengths simultaneously (useful in FRET, TR-FRET, and fluorescence polarization), chargecoupled device cameras for imaging portions of plates or whole plates, and application-specific light sources such as pulsed lasers.
Microplate readers with integrated computer and software capability allow the user to record and analyze data, however, the range of applications and analyses available may be a little more limited than the options available on an external PC. Those microplate readers that do not have integrated computer and software capabilities must be connected to an external PC for analysis of the data. While this may not be as convenient as an integrated system, it may ultimately create more options for the analysis and manipulation of data through a familiar Windows interface. Software packages sold by other vendors are proprietary, but work arounds exist that permit software and systems from different vendors to coexist.
Top 12 most important features/ factors in the decision-making process
|Software for data collection/analysis||94%|
|Product performance for intended application||87%|
|Low maintenance/operating costs||85%|
|Service and support||84%|
|Add-on functionality and upgrade capability||75%|
|Flexibility (available detection modes)||75%|
|Ease of installation||66%|
Completed Surveys: 155
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