Forskolin-induced swelling assay

The forskolin-induced swelling (FIS) assay is an industry standard assay used to quantify Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein activity, which is hampered in Cystic Fibrosis (CF) patients. At HUB we have validated the use of our CF patient-derived organoids in forskolin-induced swelling assay for the evaluation of new treatment strategies. Activation of CFTR by forskolin leads to chloride and subsequent water influx into the organoid lumen. The resulting FIS of the organoid can be measured by time-lapse confocal microscopy. Results are presented as normalized organoid swelling curves over time. The area under the curve (AUC) is determined as a measure for CFTR activity.