A rapid-scanning spectrophotometer designed for biological tissues in vitro or in vivo.

Rapid and sensitive detection of optical signals from biological materials has been very useful in studies of cell physiology and biochemistry. A rapid-scanning spectrophotometer is described here that has the following advantages: (i) it can be used in transmission or reflection modes, (ii) it can rapidly accumulate spectra and simultaneous kinetic data, (iii) it has high accuracy and sensitivity, and (iv) it can analyze and store large amounts of spectral information. Evaluations described here are aimed toward the measurement of reduction/oxidation shifts of mitochondrial cytochromes in tissues, but the flexibility of the optical components makes this spectrophotometer adaptable to the study of light absorption changes of intrinsic or extrinsic optically active molecules in a variety of light scattering preparations, tissues, and organs in vitro or in vivo.