Posted by
Craig Brideau on
URL: http://confocal-microscopy-list.275.s1.nabble.com/weird-emission-spectral-peak-of-a-blank-buffer-tp7579220p7579221.html
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Maybe the spectrometer needs to be calibrated, or the optical path is
misaligned. If you are getting signal at twice the excitation then it
could be 'wrap-around' off the grating or whatever your spectrometer uses
to split the light. Sometimes this can be because the slit in your
spectrometer is misaligned, but it could also be the optical path leading
up to the spectrometer.
Craig
On Wed, Oct 24, 2012 at 11:26 AM, yuansheng sun <
[hidden email]>wrote:
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> Dear Listers,
>
> Recently, we got two weird peaks in the emission spectrum of our blank
> buffer (1-molar Tris at pH 7.3), measured on a spectrofluometer. The Tris
> buffer is what we use to make our dye solutions to be measured on the
> spectrofluometer. It is always freshly prepared. One small peak of the
> blank buffer shows at about 20 nm plus the excitaion wavlength
> and the other huge peak appears at about twice of the excitation
> wavelength. We found this with the emission spectrum measurements using 5
> different excitation wavelengths - 250 nm, 280 nm, 285 nm 300 nm, and 350
> nm. We also observed the similar things with DI water. Any explanation
> and suggestion would be appreciated. Thanks a lot in advance.
>
> Yuansheng Sun
>