Applications of Imaging Spectroscopy in Molecular Biology: I. Screening Photosynthetic Bacteria

We have developed an imaging spectrophotometer that combines the spatial-resolving properties of a video camera with the wavelength-resolving properties of a spectrophotometer. This instrument is especially useful for screening photosynthetic bacteria, since hundreds of colonies may be analyzed simultaneously through the chromophoric properties of the photosynthetic pigments. Enhanced fluorescence mutants (possessing defective photosynthetic reaction centers) can be imaged in realtime using a silicon target camera. Mutant screening is further facilitated through imaging spectroscopy, wherein images obtained at specific wavelengths are mixed to generate pseudo images of the colonies. Digital image processing techniques can then be used to highlight distinguishing spectroscopic features of the colonies. Future applications of imaging spectroscopy to other areas of molecular biology are discussed.