A computerized device for long-term measurements of the contraction frequency of cultured rat heart cells under stable incubating conditions.

A new computer-controlled measurement system for assessing beat rates of spontaneously contracting cultured heart cells is presented. The system overcomes several disadvantages of established techniques such as: (i) lack of precise control of the environment (pH, temperature, humidity); (ii) restriction to the measurement of one culture at a time; (iii) inability to obtain long-term measurements. The beat rate is recorded by subjecting monolayer cultures to dark field illumination and recording contraction-related changes in light scattering. A maximum of environmental stability is achieved because measurements are performed in the incubator. Beat rates of up to 16 individual culture dishes can be assessed repeatedly during freely selectable time intervals. Control of the experiments, data acquisition and data analysis are carried out by a computer. The specific advantage of the method lies in the ability to measure the beat rate of several culture dishes continuously over time intervals limited only by the viability of the cultures, i. e. up to several weeks.