Force recovery in rat EDL muscle after DNA electrotransfer in vivo. The right EDL muscle of rats was electrotransferred with 5 μg pGFP-S65T (DNA+HV+LV) or only subjected to electric pulses (HV+LV). The left EDL muscle served as untreated control. Two weeks after DNA electrotransfer the animals were sacrificed and the EDL muscles were excised and placed in a force displacement transducer. Force was measured using 90 Hz pulse trains with duration of 0.5 s. Force of the treated muscle was recorded and related to force in the contralateral control muscle. Mean values with bars denoting SD are given, n = 4 muscle sets. There were no significant difference between the treated and the control muscles.