A paper has been published that investigates the difference between manually counting bacterial colonies and using automated digital colony counters. The automated digital colony counter used in the study was the ProtoCOL3, manufactured by Synoptics and available in the UK from Don Whitley Scientific.
ProtoCOL3 is an automated colony counter and zone reading system with a high specification digital camera and LED lighting. The system comes with a touchscreen PC on which to analyse sample counts. This data can then be transferred via USB.
The paper in which the ProtoCOL3 is featured is entitled “Evaluation of heterotrophic plate and chromogenic agar colony counting in water quality laboratories” (Elsevier. Hallas G, Morris P. Crossref DOI link: https://doi.org/10.1016/j.mex.2015.10.003 Published: 2015) and was published by Gary Hallas (SA Water Corporation) and Paul Monis (The University of Adelaide). Their abstract can be read below and the full paper can be read here.
The enumeration of bacteria using plate-based counts is a core technique used by food and water microbiology testing laboratories. However, manual counting of bacterial colonies is both time and labour intensive, can vary between operators and also requires manual entry of results into laboratory information management systems, which can be a source of data entry error. An alternative is to use automated digital colony counters, but there is a lack of peer-reviewed validation data to allow incorporation into standards. We compared the performance of digital counting technology (ProtoCOL3) against manual counting using criteria defined in internationally recognized standard methods. Digital colony counting provided a robust, standardized system suitable for adoption in a commercial testing environment. The digital technology has several advantages:
• Improved measurement of uncertainty by using a standard and consistent counting methodology with less operator error.
• Efficiency for labour and time (reduced cost).
• Elimination of manual entry of data onto LIMS.
• Faster result reporting to customers.
This paper acknowledges that digital colony counters like the ProtoCOL3 remove the need for manual counting and manual data entry, which can be laborious and time consuming tasks.