Ocean Optics Curie UV-VIS Emission - Manual (Page 27)

3: Using the Curie System
As shown in the figure, the shape of the fluorescence spectrum is impacted by the measurement mode
chosen. The preferred mode for fluorescence measurements is Relative Irradiance mode because the
impact of variables such as the intensity of the light source, the reflectivity of the grating and mirrors in
the spectrometer, the response of the detector, and the spectral characteristics of the sample do not affect
the shape of the spectrum. When the Curie custom software is installed and used, the software is
automatically placed in Relative Irradiance mode using the factory calibration performed for your Curie
(see
Installing Custom Curie Software to Activate Relative Irradiance Mode for instructions on installing
the Curie software from the Custom Software CD).
The first step in measuring fluorescence from your sample is to choose the excitation wavelength for your
measurement. See
Selecting the Excitation Wavelength for the options available for selecting the
excitation wavelength range.
Selecting the Excitation Wavelength
The pulsed xenon light source included in your Curie system is a broadband light source capable of
providing excitation energy throughout the UV/VIS (200 to 850 nm) region. To avoid masking your
fluorescence signal with the broadband energy from the light source, the wavelength range for excitation
can be chosen using the novel, LVF technology or discrete bandpass filters.
The Curie offers you three filtering options to select the excitation wavelength:
• Linear variable bandpass filters – See Selecting the Excitation Wavelength Range with LVF
Filters .
• Discrete bandpass filters – See Selecting the Excitation Wavelength Range with Discrete
Bandpass Filters .
• No filters – For fluorescence measurements made without filters, there is a possibility that the
broadband light source will be scattered into the detector and overlap the fluorescence emission.
You can check this by using a cuvette containing solvent only (no fluorophore) to see if your
excitation energy is scattered into the detector. The presence of peaks in the spectrum for your
solvent alone would suggest that your solvent has a background fluorescence or that excitation
energy is being scattered into your detector.
Selecting the Excitation Wavelength Range with Discrete Bandpass Filters
The Curie system provides two slots to hold the filters, one for an excitation filter and one for an emission
filter. Note that the linear variable filters must be in the No LVF position (thumbscrews positioned closest
to the end cap) to access the excitation filter slot.
If you have a 1-inch diameter bandpass filter that you would prefer to use for your measurements, you can
place it in the empty filter holder provided or replace the existing filter in one of the other filter holders.
To replace an existing filter, loosen the setscrew at the bottom of the filter holder to remove the filter,
then insert your own filter and tighten the screw. Your filter must be 1 inch in diameter to fit in the
supplied filter holder.
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