ABSTRACT
Today, fluorescence techniques is one of the most important research tools in cell biology and biochemistry. The spontaneous fluorescence of waterborne microorganisms [such as Giardia lamblia, Paramecium, and rotifer] without adding dyes is referred to in this chapter as optical natural fluorescence (ONF). The ONF spectroscopy is useful because it does not require any chemical manipulation for the sample, gives real-time results immediately from the sample reaction, and supplies information about the biological structure of the cell through its fluorophores. This technique is compatible with microscope optics and sensitive to weakly fluorescing microscopic samples. It can be used to distinguish the microorganisms from each other.
