- Thermoelectrically cooled CCD enables to detect all available wavelength simultaneously.
- Capable to detect spectra of ultra low intensity light.
- For spectrum measurement of bio/chemiluminescence and fluorescence for:
- FRET (Fluoresence Resonance Energy Transfer)
- BRET (Bioluminescece Resonance Energy Transfer)
- Quality control for luminescent/fluorescent reagents
(1) Sample cell
(1) Luminescence emitting from the sample cell is led to 45-degree angled mirror through a slit.
(2) A collimator collimates the light into a parallel beam and leads it to a diffraction grating.
(3) The grating reveal spectrum of the sample emission.
(4) A mirror converges the light onto the surface of CCD.
(5) A highly sensitive, cooled CCD camera receives the light and measures the intensity in all
available wavelengths at a time. Cooling makes it possible for spectrum measurement of very
low-level light with longer exposure time.
Highly Sensitive Spectrometer
AB-1850 LumiFluor SC
Advantages of AE-1850 LumiFluor SC
Issues for conventional spectrometers
- Commonly used spectrophotometers for bioluminescence and
chemiluminescence spectral analysis usually equipped with
photomultiplier tubes (PMT) as detectors. After the sample
emission is diffracted into several beams by a prism or a
grating, a PMT detects the light in each wavelength by se-
- The quantum efficiency of the PMT is low comparing to a
CCD, resulting bad S/N ratio. Exposure time: 10 sec.
- The time for scanning has to be extended to detect very low- Total measurement time: 10 sec.
level light. It causes to increase total measurement time, but
long measurement time causes the following:
- Increasing background noise.
- Quickly decaying emission is not measured correctly.
The LumiFluor SC system uses a high optical 1. Emission/fluorescence detection system
efficiency spectrograph and a thermoelectrically Spectral wavelength range
350 nm to 750 nm
cooled CCD detector capable of direct imaging of Exposure time
0.1 to 3600 seconds
TE cooled CCD
Capacity 2 x 106 Photons/sec, nm
full spectra, including weak spectra that require 2. Spectrograph
extended exposure times. Grating 150 lines/mm or 600 lines/mm (user
Unlike scanning spectrometer instruments that Blaze 500 nm
3. Sample compartment
required prohibitively long integration times, this Sample volume 10 μL to 100 μL
Sample cell Quartz cell, micro centrifuge tube
system achieves high S/.N spectra even for 4. Control system (External PC based)
Functions Instrument control
small sample volumes. Emission/fluorescence data analysis and
Optional excitation source
Excitation wavelength 350 nm to 500 nm, filter selectable
Source 100 W Xenon lamp
Highly Sensitive Spectrometer
Sample of Application
LumiFluor for FRET and BRET
Fluorescence Resonance Energy Transfer (FRET) and Bioluminescence Resonance Energy
Transfer (BRET) are powerful new tools for the study of protein-protein and protein-nucleic
acid. The FRET technique is based upon the transfer of light energy from an excited donor
fluorophore to an acceptor fluorophore. The distance between the two fluorophores and the
orientation of the fluorophores strongly influences the efficiency of this energy transfer, and is
characterized by the emission of light of a specific wavelength from the second fluorophore.
Fluorophore pairs such as BFP (blue fluorescent protein) and GFP (green fluorescent pro-
tein), or CFP (cyan fluorescent protein) and YFP (yellow fluorescent protein are typically
BRET is similar to FRET, but rather than using an external excitation source, the donor
fluorophore is replaced by a luciferin:luciferase complex. By choosing an appropriate lumi-
nescence and acceptor fluorophore pair, protein interactions can be measured without the
risk of damage from the excitation source.
In order to achieve higher levels of sensitivity we have developed a new thermoelectrically
cooled charge coupled device camera based spectrometer/spectrograph. Our system can
simultaneously measure the entire spectrum from 350 to 750 nm with a spectral resolution of
1 nm using only 10 to 100 μL of sample. An optional external excitation source is available
for FRET analysis, or the system may be used without external excitation for high sensitivity
Reference: Otsuji T, Okuda-Ashitaka E, Kojima S,
Akiyama H, Ito S, Ohmiya Y. (2004) Anal Biochem.,
329(2), 230-7: Monitoring for dynamic biological
processing by intramolecular bioluminescence
Fig. Spectra of BRET showing intact molecule BRET resonance energy transfer system using secreted
emission before and after cleavage at KR site
Energy from the luciferin/Vargula luciferase reaction (LH2 and Vluc) is transferred to En-
hanced Yellow Fluorescent Protein (YFP) when these species are in close proximity.
Yellow light is emitted. Once the molecule is cleaved at the lysine-arginine cleavage site,
only blue light is emitted from the luciferin/luciferase reaction.