In a capillary carrier with an inlet and an outlet, a channel is formed and extends between the inlet and the outlet. At least one capillary tube is arranged within the channel, and sealing elements, by which the capillary tube is sealingly fixed to the channel, are arranged at least near an inlet portion and an outlet portion of the capillary tube. An area is formed limited by a part of the channel, the sealing elements and the exterior of the capillary tube, which is in connection with the exterior of the carrier through a fluid communication pad, whereby a possible fluid leak across the sealing elements will be led to this area, and from there to the exterior of the carrier.