{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,27]],"date-time":"2025-11-27T13:52:44Z","timestamp":1764251564203,"version":"build-2065373602"},"reference-count":20,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2019,2,21]],"date-time":"2019-02-21T00:00:00Z","timestamp":1550707200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Automatisation and digitalisation of laboratory processes require adequate online measurement techniques. In this paper, we present affordable and simple means for non-invasive measurement of biomass concentrations during cultivation in shake flasks. Specifically, we investigate the following research questions. Can images of shake flasks and their content acquired with smartphone cameras be used to estimate biomass concentrations? Can machine vision be used to robustly determine the region of interest in the images such that the process can be automated? To answer these questions, 18 experiments were performed and more than 340 measurements taken. The relevant region in the images was selected automatically using K-means clustering. Statistical analysis shows high fidelity of the resulting model predictions of optical density values that were based on the information embedded in colour changes of the automatically selected region in the images.<\/jats:p>","DOI":"10.3390\/s19040894","type":"journal-article","created":{"date-parts":[[2019,2,22]],"date-time":"2019-02-22T03:49:44Z","timestamp":1550807384000},"page":"894","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Using Colour Images for Online Yeast Growth Estimation"],"prefix":"10.3390","volume":"19","author":[{"given":"Elias","family":"August","sequence":"first","affiliation":[{"name":"Institute of Chemistry and Biotechnology, Zurich University of Applied Sciences, 8820 W\u00e4denswil, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Besmira","family":"Sabani","sequence":"additional","affiliation":[{"name":"Institute of Chemistry and Biotechnology, Zurich University of Applied Sciences, 8820 W\u00e4denswil, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8731-0970","authenticated-orcid":false,"given":"Nurdzane","family":"Memeti","sequence":"additional","affiliation":[{"name":"Institute of Chemistry and Biotechnology, Zurich University of Applied Sciences, 8820 W\u00e4denswil, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,2,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1016\/j.tibtech.2012.03.001","article-title":"Advances in shaking technologies","volume":"30","year":"2012","journal-title":"Trends Biotechnol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"17390","DOI":"10.3390\/s140917390","article-title":"Application of an Online-Biomass Sensor in an Optical Multisensory Platform Prototype for Growth Monitoring of Biotechnical Relevant Microorganism and Cell Lines in Single-Use Shake Flasks","volume":"14","author":"Ude","year":"2014","journal-title":"Sensors"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Kim, S.D., Koo, Y., and Yun, Y. 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