Choosing the best microplate reader

Which detection modes do I need?

Once the relevant applications have been identified, the next step is determining which detection modes are required.

Different assay types rely on different detection modes, making this one of the most important aspects of choosing the best microplate reader.

Standard Detection Modes

Absorbance

Absorbance remains one of the most widely used detection technologies in life science laboratories and includes applications such as ELISAs, Bradford assays, BCA assays, Lowry protein quantification, nucleic acid measurements, and OD600 microbial growth. 

When evaluating an absorbance microplate reader, researchers should consider wavelength range and selection technology. Filter-based systems are ideal for laboratories running routine assays, whereas readers incorporating UV/vis spectrometers allow users to select virtually any wavelength or acquire a full spectrum in < 1 second/well without changing hardware components, providing greater flexibility for method development and future assays.

Fluorescence intensity

Fluorescence intensity has become one of the most important detection modes because it offers significantly greater sensitivity than absorbance.

Fluorescence-based assays are widely used in cell biology, molecular biology, biochemistry, and drug discovery to measure cell viability, enzyme activity, intracellular signaling, reactive oxygen species, protein interactions, and nucleic acid concentrations. 

The sensitivity of fluorescence measurements depends heavily on optical design. Instruments with LVF Monochromator technology provide researchers with the ability to access both filter-like sensitivity and monochromator flexibility in one system.

Luminescence

Luminescence is frequently considered the most sensitive detection technology available on a microplate reader. Because there is no excitation source, background interference is minimised, resulting in exceptional sensitivity and broad dynamic range. This makes luminescence plate readers particularly attractive for ATP assays, luciferase reporter gene assays, receptor-ligand interaction studies, cell viability measurements, and many drug discovery applications.

Advanced detection modes 

While absorbance, fluorescence intensity, and luminescence cover most routine laboratory requirements, advanced research applications often require specialized technologies.

Fluorescence Polarization

Fluorescence polarization is commonly used to study molecular interactions and binding events. Because changes in polarization are directly related to molecular size and mobility, this technology has become a valuable tool for competitive binding assays, receptor studies, and enzyme activity measurements.

Time-resolved fluorescence (TRF) & TR-FRET

By introducing a delay between excitation and measurement, Time-resolved fluorescence (TRF) significantly reduces background noise and improves assay sensitivity. This makes it particularly useful for biomarker detection, immunoassays, and cellular metabolism studies.

TR-FRET combines time-resolved fluorescence with Förster resonance energy transfer and has become a powerful technique for studying protein-protein interactions, receptor binding events, kinase activity, and high-throughput screening assays especially in pharmaceutical and biotechnology research.

AlphaScreen

AlphaScreen® and AlphaLISA® technologies have also become widely adopted in drug discovery and assay development because they enable highly sensitive, homogeneous assays without washing steps. Laboratories planning to enter these application areas should ensure that their chosen reader supports such technologies.

Nephelometry

Nephelometry is a light-scattering technique used to detect and quantify insoluble particles suspended in a solution. Unlike absorbance measurements, which quantify light passing through a sample, nephelometry measures the light scattered by particles present in the well. Nephelometry is widely used to assess compound solubility, aggregation, and precipitation. 

Sensitivity or flexibility: filters versus monochromators

One consideration that is often overlooked when choosing the best microplate reader is the optical technology used for wavelength selection.
Filter-based readers are traditionally regarded as the benchmark for assay sensitivity. Optical filters transmit very specific wavelength ranges with high light transmission, making them particularly advantageous for demanding applications such as TR-FRET, or AlphaScreen®.

Monochromator-based readers offer a different advantage. Instead of relying on multiple dedicated filters, monochromators allow researchers to freely select excitation and emission wavelengths. Readers with monochromators enable in addition excitation and emission spectral scanning. This flexibility makes them particularly attractive for assay development laboratories and facilities that frequently use different fluorophores and assay chemistries.

BMG LABTECH’s patented LVF Monochromator uses linear variable filters to the select light of distinct wavelengths and bandwidths.

Modern microplate readers such as the VANTAstar and CLARIOstar Plus can combine both technologies in a single instrument. This approach allows researchers to maximize sensitivity when required while maintaining the flexibility needed for future assay development.

Single-mode or multi-mode reader?

Another important decision is whether a single-mode or multi-mode reader best suits laboratory requirements.

Single-mode readers are designed around a specific detection technology and are particularly useful when measurements are highly standardized and unlikely to change. Laboratories performing routine assays or specialized long-term kinetics often benefit from the simplicity and cost-effectiveness of a dedicated instrument.