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Many absorbance microplate readers perform basic assays such as ELISA and enzyme kinetics. However, more complicated assays such as direct nucleic acid and protein quantification, cell-based assays, growth studies, or temperature-dependent kinetic measurements require a specialized ultraviolet/visible (UV/Vis) optical system, plus shaking or incubation, functions not found in basic absorbance readers. Finding a balance between standard and complex assay capability is difficult when a reader is shared among multiple researchers.

The Eon Microplate Spectrophotometer is a compact absorbance reader that combines single-channel optics, multiple shaking modes, and temperature control, and also accommodates a variety of labware to increase flexibility in assay choice and among multiple users.

Eon features internal monochromator-based, single-channel optics that allow filter-free wavelength selection from 200 to 999 nm in 1 nm increments and spectral scanning. The single-channel optics make well area scanning possible, which is important in the larger well diameter of 6- to 48-well plates. Area scanning allows multiple measurements in a grid pattern, useful in obtaining data from all areas of the larger wells, often important in bacterial growth studies. In a monochromator optical system, white light from a xenon flash lamp is pre-separated via order-sorting filters and directed into the entry slit of the monochromator, where a diffraction grating separates individual, selectable wavelengths. The selected wavelength exits the monochromator and is directed by a fiber optic cable through the sample to a photodiode, which quantifies the signal. A reference detector ensures adequate signal for each measurement. Samples in microplates are measured through a vertical pathlength. Pathlength correction to a standard 1 cm is available via Gen5 software to compare results to standard cuvette readings.

A cuvette port is included for horizontal sample orientation and fixed 1 cm optical pathlength. The instrument may be used with BioTek’s Take3 micro-volume plate to measure 2 µL samples, or integrated into robotic systems for automated processing.

BioTek’s 4-zone natural convection heating system provides temperature control to 65 C. User-definable shaking parameters include linear, orbital, and double orbital shaking, with variable intensities and intervals to meet the requirements for a multitude of assays. Typical applications include nucleic acid and protein quantification, cell proliferation assays, cytotoxicity studies, ELISA, enzyme kinetics, endotoxin analysis, and PAMPA, among others.