Spectral Characteristics of Biologically Significant Molecules

Turn on a dual beam recording spectrophotometer and allow it to warm up as directed by the manufacturer. Both the tungsten and deuterium bulbs should be turned on. 

Prepare an absorbance spectrum of this solution in the above spectrophotometer operating between the wavelengths of 240 and 500 nm. Caution should be taken to change the light source at 340 nm from the tungsten to the deuterium source. Failure to do this will result in a very erratic spectrum below this wavelength. 

Similar experiments may be performed using RNA, DNA, cytochrome C, hemoglobin, and the reduced and oxidized forms of NAD, FMN, and FAD. 

Allan G. Gornall, Charles J. Bardawill, and Maxima M. David, J. Biol. Chem., 177 751-766 (1949). Determination of Serum Proteins by Means of the Biuret Reaction. Oliver H. Lowry, Nira J. Rosebrough, A. Lewis Farr, and Rose J. Randall, J. Biol. Chem., 193 265-275 (1951). Protein Measurement with the Folin Phenol Reagent. Ennis Layne, Methods EnzymoL, 3 447-454 (1957). Spectrophotometric and Tur-bidimetric Methods for Measuring Proteins. 

Toribara, and Huber Warner, Anal. Chem., 28 1756-1758 (1956). Microdetermination of Phosphorus. 

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