Microplate Readers

For any researcher conducting biological assays, no lab would be complete without the microplate reader, a staple instrument widely used across both industry and academia. Commonly referred to as plate readers, these analytical instruments are a type of spectrophotometer that measures light absorbance, fluorescence, or luminescence of samples in multiwell microplates. The most common plate formats are 96- or 384-well, but many plate reader models can also accommodate sizes from 6- to 1536-well. In contrast to single cuvette measurements, plate readers enable the high throughput analysis of many samples per run, improving the productivity and reproducibilty of experiments. In this catalog, we have categorized many readers across leading manufacturers with the goal of helping scientists discover and compare the most appropriate instruments for their research.

Absorbance Plate Readers

Absorbance in the ultraviolet (UV) to visible range is often used to quantify analytes such as proteins, nucleic acids, and small molecules. Absorbance plate readers are designed for this very purpose and are well-suited for routine colorimetric assays. While their detection options may be limited to the absorbance readings, many of these instruments are compact and come with additional built-in features, such as touch screen interfaces, plate shakers, cuvette ports and multiple plate capabilities.

Multimode Plate Readers

For laboratories that need more functionality in addition to UV-vis absorbance detection, multimode readers are advanced instruments that offer expanded capabilities. These are versatile instruments that allow two or more detection applications, including fluorescence, luminescence, or both. They can be further categorized based on application as follows:

Fluorescence

Using lasers, fluorescence-enabled readers shine light at samples within microplates and subsequently detect the intensity of light emitted. The resulting signals are then processed to quantify the amount of analytes within the sample. In addition to fluorescence intensity, many readers can also perform other fluorescence measurements, including fluorescence polarization, time-resolved fluorescence, HTRF (Homogeneous Time-Resolved Fluorescence), TR-FRET (Time-Resolved Fluorescence Resonance Energy Transfer). Fluorescence plate readers are essential when carrying out fluorometric assays, such as in cell viability and proliferation assays, certain enzyme assays, ELISAs, quantitation of fluorescent labels, and more.

Luminescence

Luminescence-enabled readers detect and measure luminescence, which is light generated by a chemical (chemiluminescence) or biological reaction (bioluminescence). This functionality is necessary for applications such as luciferase reporter assays, bioluminescence resonance energy transfer (BRET), and flash and glow luminescent assays.

Many multimode readers can flexibly accommodate both fluorescent and luminescent measurements. Further, some readers are also built to carry out other applications like live cell imaging, Alpha screen, and Western blot detection. Labs that routinely conduct these experiments may want to consider a multimode reader over an absorbance plate reader.


The image above highlights some common specifications and features one may consider when choosing a new microplate reader.

Multiplex Plate Readers

Multiplex-enabled readers and imagers combine differentially dyed fluorescent microsphere sets to multiplex many unique assays within a single sample. These platforms can enable the detection of hundreds of protein or nucleic acid analytes from a single sample, offering researchers the ability to efficiently generate more data. Unlike standard plate readers, multiplex readers generally operate at specific wavelengths that accommodate compatible multiplex assay reagents. A variety of protein and nucleic acid applications are possible with multiplexing, such as immunoassays, genotyping, and biomarker quantitation.