Application of Fourier transform infrared spectroscopy to perform noninvasive measurements

Animal cell cultures have previously been shown to generate maximal amounts of high value proteins when maintained in a controlled environment with low and constant concentrations of nutrients and wastes. Recent studies have indicated that at least 17 nutrients must be controlled so as to prevent initiation of apoptosis or programmed cell death. We present here the development and application of a near-infrared spectroscopic (NIRS) monitoring scheme which can provide rapid, simultaneous, and noninvasive measurement of 19 cellular nutrients and wastes. The components include glucose, lactate, ammonia, pyruvate, glutamine and 14 other amino acids. Spectroscopic calibrations were generated for a standard culture medium (DMEM) with varying concentrations of all of the high concentration components. Accurate measurements of these 19 components could be accomplished in the absence or presence of 10% horse serum. When the presence of serum was included into the calibration development. measurements were as accurate with or without serum. Analytes with concentrations as low as 0.3 mM could be reliably quantified. These results demonstrate the feasibility of application of NIRS for monitoring the large number of varying components of cell cultivations.