Pigments produced by bacteria do have some absorbance at the wavelengths (e.g. 625 / 660/ 600 nm) which are used for measurement of microbial growth. How can one minimize the interference from these pigments while measuring the growth through photometry?
Helo Vijay
The subject is not so simple because you have two principles of measurements colliding. The growth is more or less a transmission while the colour effects more the adsorption. First of all: for linear growth measurement, the extinction needs to be under 0,8 AU otherwise the results ge to non-linear. I would think that lowering the cell-density as far as possible would be the first idea. Did you take a complete UV-Vis-spectra?
Usually pigments have maximums in the UV-area, mostly higher than the Vis- maximas, maybe you can compare the result to a non-coloured MO of the same cell-density to have a blank, I would think, that you migth find measurable levels of extinction in UV 200-400nm.
You can check if there is a flourescence occuring, this would give you a unique possibility for measuring.
If you cannot avoid high cell densities, you can also measure the amount of reflected light in the desired Vis-wavelengths
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