Construction of a Low-cost Mobile Incubator for Field and Laboratory Use

Abstract

Incubators are essential for a range of culture-based microbial methods, such as membrane filtration followed by cultivation for assessing drinking water quality. However, commercially available incubators are often costly, difficult to transport, not flexible in terms of volume, and/or poorly adapted to local field conditions where access to electricity is unreliable. The purpose of this study was to develop an adaptable, lowcost and transportable incubator that can be constructed using readily available components. The electronic core of the incubator was first developed. These components were then tested under a range of ambient temperature conditions (3.5 °C-39 °C) using three types of incubator shells (polystyrene foam box, hard cooler box, and cardboard box covered with a survival blanket). The electronic core showed comparable performance to a standard laboratory incubator in terms of the time required to reach the set temperature, inner temperature stability and spatial dispersion, power consumption, and microbial growth. The incubator setups were also effective at moderate and low ambient temperatures (between 3.5 °C and 27 °C), and at high temperatures (39 °C) when the incubator set temperature was higher. This incubator prototype is lowcost (< 300 USD) and adaptable to a variety of materials and volumes. Its demountable structure makes it easy to transport. It can be used in both established laboratories with grid power or in remote settings powered by solar energy or a car battery. It is particularly useful as an equipment option for field laboratories in areas with limited access to resources for water quality monitoring.

Assessing Drinking Water Quality at the Point of Collection and within Household Storage Containers in the Hilly Rural Areas of Mid and Far-Western Nepal

“…We performed the positive control by adding a small portion of animal feces into a water sample and the negative control using sterile water. More information about the field laboratories' set up and operation is published elsewhere [10,18].…”

Evaluation of the novel substrate RUG™ for the detection ofEscherichia coliin water from temperate (Zurich, Switzerland) and tropical (Bushenyi, Uganda) field sites

“…33 Ambient-temperature incubation 34 or field incubators, such as those developed by Schertenleib et al 2019 offer a potential low-cost solution. 35 More research is needed regarding the possibility of ambient-temperature incubation with temperatures higher than 24°C.…”

A Simple Off-Grid Incubator for Microbiological Water Quality Analysis

“…The above analysis provides evidence that this simple incubation method is sufficiently reliable and practical for use in low-resource settings. This is of particular relevance in consideration of its relative low-cost (approximately $10 USD) in comparison to other recently-developed low-cost (approximately $300 USD) field incubators [14]. Based on visual observations during fieldwork, the EPS cooler did not break during use, and leakage was not observed from the polystyrene water bottles.…”