Aquatic Microbial Ecology

Confocal laser scanning microscopy (CLSM) was used to examine living organisms within marine biofilms growing on microscope slides and on natural opaque and uneven substrata such as rocks and shells. The results were compared to images of identical fields observed under transmitted light and phase contrast microscopy and scanning electron microscopy. Confocal microscopy proved superior in several respects: (1) It gave clear images of organisms even if they were overlaid with a thick layer of mucus, other organisms and debris. (2) It did not require the biofilm to be disrupted or dried and allowed samples to be re-examined at intervals. (3) It could also distinguish living (fluorescing) organisms from dead…