The Gemini XS Dual-Scanning Microplate Spectrofluorometer can perform a variety of fluorescent applications as well as some time-resolved fluorescent and luminescent assays. The extreme flexibility and high sensitivity of the Gemini XS make it appropriate for applications within the fields of biochemistry, cell biology, immunology, molecular biology, and microbiology.
The Gemini XS uses two holographic diffraction grating monochromators which allow for individual optimization of wavelengths for both excitation and emission. The dual-scanning capability can also be used to determine excitation and emission settings for new fluorescent probes. Mirrored optics focus the light into the sample volume and cutoff filters are used to reduce stray light and minimize background interference. The light source is a high-powered Xenon flashlamp; additional flexibility is provided by allowing a variable number of lamp flashes per read.
The Gemini XS also has two secondary modes that can be used for limited development of glow luminescence or time-resolved fluorescence assays. The performance of these two modes is not comparable to dedicated luminescence or time-resolved fluorescence instruments. Microplates having 6, 12, 24, 48, 96, and 384 wells can be used in the Gemini XS. Fluorescent detection is achieved from the top, through the entire depth of sample in the microplate well. Detection of species collected on membrane plates is also possible. One plate carrier adapter is provided with the instrument. The adapter is required for optimum performance with standard 96- and 384-well format microplates for all applications. The dynamic range of detection is from 10-6 to 10 -11 molar fluorescein. Variations in measured fluorescence values are virtually eliminated by internal compensation for detector sensitivity, photomultiplier tube voltage and sensitivity, as well as excitation intensity. Temperature in the microplate chamber is isothermal, both at ambient and when the incubator is turned on. When the incubator is on, the temperature may be controlled from 4°C above ambient to 45°C. The contents of the wells in a microplate can be mixed automatically by shaking before each read cycle, which makes it possible to perform kinetic analysis of solid-phase, enzyme-mediated reactions such as a kinetic ELISA. The Gemini XS is controlled by an external computer running SoftMax ®Pro software which provides integrated instrument control, data display, and statistical data analysis. The Gemini XS cannot be operated without the computer and SoftMax Pro software.