A new microcatheter enables microcalorimetric assessment of thermogenesis after stimulation in cell cultures.

A new, inexpensive technique facilitates the observation of long-lasting effects (> 2 h) of thermogenic agents on cell cultures. A special microcatheter enables addition of hormones or pharmacologic agents to biological samples during microcalorimetric analysis using a ThermoMetric ThermalActivityMonitor without removing the sample ampoules from the measuring position. Technical modification of the calorimeter is not required. Baseline stability with the connected catheter is +/- 0.2 microW over 10 h. The error of the method of catecholamine induced thermogenesis in white adipocytes is 13.4% (C.V.).