How can I find the peak showing the highest OD value of an absorbance spectrum?

October 24, 2011

In BMG LABTECH's MARS Data Analysis Software, it is possible to find the peak showing the highest OD value of an absorbance spectrum once the entire spectrum has been measured.

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Dr EJ Dell
PhD, Sales Manager Northwest

This is especially useful for ELISA assays. In ELISA kit manuals a specific wavelength is often recommended. However, these recommendations are often based upon measurements made with older tungsten flash lamps not found on the modern microplate readers used in labs today and the recommended wavelength may therefore not show peak with the highest OD value.


BMG LABTECH uses sophisticated high power xenon flash lamps, which are much more sensitive and may require a slightly different wavelength for optimal results. The correct wavelength needed for such assays can be easily found by measuring a complete spectrum using the UV/Vis absorbance spectrometer incorporated into the Omega Series, PHERAstar FS and SPECTROstar Nano microplate readers. One of the great features of the UV/Vis absorbance is the ability to read a full UV/Vis spectrum from 220-1000nm in less than 1 sec/well.


Once you have measured the entire spectrum, MARS can automatically set the analysis cursor to the highest peak recorded. It is that simple! Open the recorded test run, select a spectrum in the spectrum view, and add wavelengths for all local maxima in the dialog. All peaks will then be indicated automatically. This will help to increase the dynamic range of the assay and lead to better results.