AN ANALYSIS OF PORPHYRIDIUM ABSORPTION BANDS WITH A DIGITAL SPECTROPHOTOMETER

Abstract— –Numerical absorbance values treated by a computer allow one to easily obtain precise absorption spectra from intact cells or extracts. An attempt has been made to determine the number and position of the individual bands by the difference spectra and the fourth derivative method. These two methods resulted in an accurate curve resolution with single Gaussian components and yielded relative proportions of chl a forms in Porphyridium.