ABSTRACT
A modern technique to categorize bacteria by Infrared (IR) spectra utilizes an Fourier Transform Infrared system and computer software. Bacteria grown on a culture medium is harvested with a spatula and dispersed in a drop of clean water. The water is then transferred to a ZnSe plate and dried to form a transparent sheet of bacteria on the plate. IR spectroscopy is often utilized to study the higher order structure of biological samples. The diffuse reflection technique was chosen because diffuse reflection of the radiation was expected at the surface of the wing, since the butterfly wing does not have a uniform film structure but a complicated structure with pores and squamous or scale-like cells. Dichroic ratios were determined in order to investigate the anomaly seen in the 25%–60% stretching range. Keratin is an elastic material which can be stretched but resumes its original length when the stretching force is removed.
