ABSTRACT
Lemmerman in response to nitrogen starvation. These authors pioneered the novel combination of infrared (IR) spectroscopy, with its chemical identiÞcation, with studies of algal physiology. Additionally, Giordano et al. compared these data with chemical analysis. However, due to the novelty of the methodology, they started with studying dried microalgal samples. Here we present IR microspectroscopy data for living
Euglena gracilis
single cells at high spatial resolution (5
m
m) for cells in a moist environment. IR vibrational spectroscopy is a well-established, nondestructive tool to examine and identify chemistry
in biological samples. IR radiation is absorbed by molecules with functional groups vibrating at similar frequencies. Unique absorption signatures exist for different chemicals including, for example, sugars, lipids, and proteins. Fourier Transform Infrared (FTIR) microspectroscopy is a very efÞcient example of this methodology to investigate small samples (100
m
m or less) that has become readily available with recent advances in optical and computer technology.
