BACKGROUND: Multiplexed milliliter-scale chemostats are useful for measuring cell physiology under various degrees of nutrient limitation and for carrying out evolution experiments. In each chemostat, fresh medium containing a growth rate-limiting metabolite is pumped into the culturing chamber at a constant rate, while culture effluent exits at an equal rate. Although such devices have been developed by various labs, key parameters - the accuracy, precision, and operational range of flow rate - are not explicitly characterized. METHODS: Here we re-purpose a published multiplexed culturing device to develop a multiplexed milliliter-scale chemostat. Flow rates for eight chambers can be independently controlled to a wide range, corresponding to population doubling times of 3~13 h, without the use of expensive feedback systems. RESULTS: Flow rates are precise, with the maximal coefficient of variation among eight chambers being less than 3%. Flow rates are accurate, with average flow rates being only slightly below targets, i.e., 3%-6% for 13-h and 0.6%-1.0% for 3-h doubling times. This deficit is largely due to evaporation and should be correctable. We experimentally demonstrate that our device allows accurate and precise quantification of population phenotypes. CONCLUSIONS: We achieve precise control of cellular growth in a low-cost milliliter-scale chemostat array, and show that the achieved precision reduces the error when measuring biological processes.
BACKGROUND: Multiplexed milliliter-scale chemostats are useful for measuring cell physiology under various degrees of nutrient limitation and for carrying out evolution experiments. In each chemostat, fresh medium containing a growth rate-limiting metabolite is pumped into the culturing chamber at a constant rate, while culture effluent exits at an equal rate. Although such devices have been developed by various labs, key parameters - the accuracy, precision, and operational range of flow rate - are not explicitly characterized. METHODS: Here we re-purpose a published multiplexed culturing device to develop a multiplexed milliliter-scale chemostat. Flow rates for eight chambers can be independently controlled to a wide range, corresponding to population doubling times of 3~13 h, without the use of expensive feedback systems. RESULTS: Flow rates are precise, with the maximal coefficient of variation among eight chambers being less than 3%. Flow rates are accurate, with average flow rates being only slightly below targets, i.e., 3%-6% for 13-h and 0.6%-1.0% for 3-h doubling times. This deficit is largely due to evaporation and should be correctable. We experimentally demonstrate that our device allows accurate and precise quantification of population phenotypes. CONCLUSIONS: We achieve precise control of cellular growth in a low-cost milliliter-scale chemostat array, and show that the achieved precision reduces the error when measuring biological processes.
Authors: Chris N Takahashi; Aaron W Miller; Felix Ekness; Maitreya J Dunham; Eric Klavins Journal: ACS Synth Biol Date: 2014-08-01 Impact factor: 5.110
Authors: Robin Green; Lin Wang; Samuel F M Hart; Wenyun Lu; David Skelding; Justin C Burton; Hanbing Mi; Aric Capel; Hung Alex Chen; Aaron Lin; Arvind R Subramaniam; Joshua D Rabinowitz; Wenying Shou Journal: PLoS Biol Date: 2020-08-24 Impact factor: 9.593