Detection of Fresh and Fossil Pollen with Fluorochromes

Abstract

IN recent years fluorescence microscopy has proved useful in bacterial identification and other clinical diagnostic procedures including the fluorescent antibody technique. Various fluorochromes have also been used in identifying soil bacteria1 or distinguishing them from soil humus2. Richards and Miller3 and Richards et al.4 reported that staining the tubercle organism with auramine O markedly enhanced its visualization, made possible the observation of large fields at low magnification, and thus increased the possibility of obtaining positive diagnoses. Some of these uses and others have been reviewed by Perner5. During examination of foliar penetration and movement of fluorescent dyes by fluorescence microscopy6–12 we observed that pollen grains entangled in the trichomes of Prosopis juliflora (mesquite) fluoresced brilliantly. The use of acridine orange in enhancing morphological detail of fresh pollen grains was afterwards described by Ratcliffe et al.13. The question at once arose as to whether fossil pollen in soil and sediment samples would respond in the same fashion.