Non-contact determination of the viscoelastic properties of agar culture media by Brillouin spectroscopy

Abstract

This study aimed to investigate the potential of Brillouin spectroscopy as a non-contact and real-time tool for measuring the viscoelastic properties of agar culture media and using them to determine the percentages of their different components. The Brillouin spectrum of media samples with varying concentrations of different components was successfully acquired. A custom-designed refractometer was employed for assessing the refractive index of the gels. The study shows that the Brillouin spectrum and viscoelastic properties of the media vary in dependence on the concentration of their different components in a predictable and controllable way and that the variation is different for each of the additives tested. This approach has the advantage of correlating to the component percentages, providing a non-contact method for evaluating the evolution of the culture medium in real-time, without disturbing the growth of cells or microorganisms. The results of this study have the potential to encourage the design of new tools and methods targeting the prediction, measuring, and control of agar plate behavior during cell culture. This could include measuring and maintaining optimal humidity conditions for maintaining suitable agar plates for cell culture or monitoring cell growth by measuring the consumption of each substance.