Gemini EM

Microplate Spectrofluorometer

 
The new Gemini EM microplate spectrofluorometer builds on the successful Gemini platform. This next generation reader incorporates all of the high performance features of the Gemini XS with new capabilities.

applications

• Chemotaxis membrane migration assays
• Nucleic acid quantitation
• Cytoxicity assays
• SNP genotype detection and molecular beacons
• Enzyme activity
• Cellular and molecular binding studies
• CatchPoint® cAMP Assay Kit

features

• Top and Bottom Reading Optics—The top/bottom-reading optical design of the Gemini EM allows for measurements for both solution and cell-based assays. With the click of a button, the Gemini EM can be switched between top- and bottom-reading modes.
• Dual Monochromators—The right pair of excitation and emission wavelengths is always available because the dual monochromators allow the selection of any wavelength in 1 nm increments. New fluorophores can easily be evaluated without purchasing additional filters.
• Wavelength Scanning—The most sensitive results are achieved by using optimal excitation and emission wavelengths. Literature wavelengths are often based on results from wavelength-limited, filter-based readers. Wavelength scanning ensures that the most sensitive assay conditions are used.
• Well Scanning—Gemini EM can report a single point from the well center, or multiple data points from the bottom of large well tissue culture plates. This provides high sensitivity for cell-based assays and is ideal for chemotaxis migration assays.
• Auto PMT Gain—Because a single microplate often presents a range of fluorescence intensities greater than three orders of magnitude, Gemini EM features "Auto PMT Gain" to avoid saturating the photomultiplier tube. The signal is calibrated against an internal standard, so the reported RFU values of individual samples can be accurately compared.

SoftMax® Pro Software, included with every Gemini EM

SoftMax Pro allows the selection of excitation and emission values from the literature and the simple input of the values for the monochromator settings. If the recommended wavelengths for the fluorophore of interest are not known, both the excitation and emission spectra can be easily scanned to determine the optimal settings.

No hardware changes of any kind are required to change modes of operation from standard fluorescence to luminescence, or well-scanning. All it takes is the click of a mouse.

		Figure 1. Optics of Gemini EM for top and bottom reading.

Gemini's dual monochromator design—an excitation monochromator (A) and emission monochromator (B)—allows user-defined variable wavelength settings. A high-powered xenon flash lamp (C) maximizes excitation energy. It sends light through a movable scanning grating (D) which selects the desired excitation wavelength. The light is passed through 1 mm fiber optic bundles (E) to elliptical focusing mirrors (F) that maximize light collection efficiency for superior sensitivity and send the beam to a microplate well (G). If fluorescent molecules are present, the light of the emission wavelength is emitted back out to focusing mirrors (H) that direct the light through 4 mm fiber optic bundles (J) to the emission scanning grating (K). The desired wavelength of light is then detected by the photomultiplier tube, or PMT (L). The PMT passes the fluorescence signal through the Gemini's electronics, creating the signals that result in data points collected by SoftMax Pro software.

The bottom-read optics of the Gemini EM offer the benefits of the Gemini XS with enhanced sensitivity for cell-based assays and the ability to detect cells adhering to the bottom of the membrane in chemotaxis assay migration plates.

Specifications**

fluorescence photometric performance
Dual Scanning Monochromator	250-850 nm
Bandwidth (Excitation & Emission)	9 nm
Scanning Provided Over Full Range	1 nm increment selection
Top Read Sensitivity	3.0 fmol/well FITC 200 µl in 96 wells
Bottom Read Sensitivity (Signal 3X Std. Dev. of Baseline)	8.0 fmol/well FITC 200 µl in 96 wells
luminescence (secondary mode)
Sensitivity	110 amol/well alkaline phosphatase (obtained with Emerald II™ reagent from Tropix, a Perkin Elmer Company)
TRF (secondary mode)
Wavelength Range	250-850 nm
Data Collection	50-1450 µsec, 200 µsec increments
Sensitivity	0.5 fmol/well Eu-chelate (obtained with the DELFIA® reagent from Perkin Elmer by using a 384-well plate)
general photometric performance
Microplate Formats	6-, 12-, 24-, 48-, 96-, and 384-well
Light Source	Xenon flash lamp (1 joule/flash)
Detector	Photomultiplier (R-3896)
Read Time	96 wells in < 15 seconds (measurement type may extend read time)
Shaker Time	0 to 999 seconds
Temperature Control (Chamber)	Ambient + 4 °C, to 45 °C

*U.S. Patent Number 5,959,738; 6,097,025; 6,232,608B1; 6,236,456B1;6,313,471B1; and 6,316,774B1.
**Specifications subject to change.