Quantitative infrared photoanalysis of selected bacteria.

A technique to measure transmitted infrared radiation from minute biological systems is described. Infrared color film was exposed by radiation transmitted through bacterial colonies. The resultant photographic image was unique for each species of bacteria examined and spectral analysis of the image provided differential light emission patterns which could be quantitated. A formula for developing numerical comparisons among bacterial colonies was provided. The results of this numerical procedure gave quantitative relationships for the total infrared data from each microbial colony and made possible the differential identification of ten species of medically significant bacteria.