DIFFERENTIAL LIGHT SCATTERING - A PHYSICAL METHOD FOR IDENTIFYING LIVING BACTERIAL CELLS

Differential light scattering techniques appear to represent an attractive physical method for the rapid identification of various microorganisms. Certain general results of inverse scattering theory suggest strongly that characteristic of each distinct microorganism that scatters light is an essentially unique scattering pattern, i.e., unique differential scattered intensity and polarization. Although a mathematically rigorous inversion procedure seems impractical at this time, the use of detailed differential scattered intensity data as an identification fingerprint shows considerable. promise. Published measurements on nonbiological scatterers confirm this possibility. A variety of calculations are presented that contrast the expected scattering characteristics of certain microorganisms such as Bacillus subtilis, B. anthracis, Staphylococcus epidermidis, S. aureus, Escherichia coi, and the spores of B. mogaterium and B. cereus. Experimental and instrumentation difficulties and possible procedures are discussed. A review and elaboration of some applicable features of Rayleigh-Gans scattering are included as an appendix. © 1968 Optical Society of America.