| abstract |
Microbial growth assays are carried out utilizing assay apparatus having a base plate with a plurality of microbial growth assay wells, each well having a liquid content of 30 μl or less. Electrodes are coupled together through the wells and electrical connectors are connected to the electrodes to allow the effect of the content of the wells to be measured by measuring the capacitance or resistance or both between the electrodes at each well, with the change in the capacitance or resistance in each well over time being correlated with the extent of growth of a bacterium introduced into the well with a growth medium. The small size of the microwells causes the growth of bacteria in the well to quickly show a change in the electrical properties of the well, particularly in the capacitance or resistance between the electrodes at each well, with growth to saturation occurring for common bacteria such as E. coli in a few hours or less. High density base plates may be tested with a large variety of substances that may have an effect on the growth of the bacteria in the well over a relatively short period of time, allowing high throughput while maintaining the accuracy of the test. |