ODX: a Fitness Tracker-Based Device for Continuous Bacterial Growth Monitoring

Authors

Venkata V.B. Yallapragada, Cancer Research@UCC, University College Cork, Cork T12 XF62, Ireland
Uday Gowda, Centre for Advanced Photonics and Process Analysis, Cork Institute of Technology, Cork T12 P928, Ireland; Tyndall National Institute, Cork T12 R5CP, Ireland
David Wong, Cancer Research@UCC, University College Cork, Cork T12 XF62, Ireland
Liam O'Faolain, Centre for Advanced Photonics and Process Analysis, Cork Institute of Technology, Cork T12 P928, Ireland; Tyndall National Institute, Cork T12 R5CP, Ireland; Scottish Universities Physics Alliance, School of Physics & Astronomy, St Andrews KY16 9SS, UKFollow
Mark Tangney, Cancer Research@UCC, University College Cork, Cork T12 XF62, Ireland
Ganga C.R. Devarapu, Centre for Advanced Photonics and Process Analysis, Cork Institute of Technology, Cork T12 P928, Ireland; Tyndall National Institute, Cork T12 R5CP, Ireland; Scottish Universities Physics Alliance, School of Physics & Astronomy, St Andrews KY16 9SS, UKFollow

ORCID

https://orcid.org/0000-0003-1160-7441

Document Type

Preprint

Disciplines

Biological and Chemical Physics | Biophysics | Biotechnology | Life Sciences | Physics

Publication Details

Analytical Chemistry, vol. 91. no. 19. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Analytical Chemistry after technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.analchem.9b02628

Abstract

Continuous monitoring of bacterial growth in aqueous media is a crucial process in academic research as well as in the biotechnology industry. Bacterial growth is usually monitored by measuring the optical density of bacteria in liquid media, using benchtop spectrophotometers. Due to the large form factor of the existing spectrophotometers, they cannot be used for live monitoring of the bacteria inside bacterial incubation chambers. Additionally, the use of benchtop spectrometers for continuous monitoring requires multiple samplings and is labour intensive. To overcome these challenges, we have developed an optical density measuring device (ODX) by modifying a generic fitness tracker. The resulting ODX device is an ultra-portable and low-cost device that can be used inside bacterial incubators for real-time monitoring even while shaking is in progress. We evaluated the performance of ODX with different bacterial types and growth conditions and compared it with a commercial benchtop spectrophotometer. In all cases, ODX showed comparable performance to that of the standard benchtop spectrophotometer. Finally, we demonstrate a simple and useful smartphone application whereby the user is notified when the bacterial concentration reaches the targeted value. Due to its potential for automation and mass production, we believe that the ODX has a wide range of applications in biotechnology research and industry.

Recommended Citation

Yallapragada, V. V. B., Gowda, U., Wong, D., O’Faolain, L., Tangney, M. and Devarapu, G. C. R. (2019) 'ODX: a fitness tracker-based device for continuous bacterial growth monitoring', Analytical Chemistry, 91(19), pp. 12329–12335. doi: 10.1021/acs.analchem.9b02628