Capillary device

摘要

A cross or T-shaped device is disclosed for use in capillary electrophoresis or capillary chromatography. The device includes a first capillary tube and a second capillary tube connected to the first tube at a point between the two ends of the first tube so that the contents flowing in the second tube will mix with a fluid flowing in the first tube. The two tubes enclose spaces with cross-sectional dimensions less than about 200 microns. The two tubes are connected so that there is substantially no dead space at the connection. The device is made by boring a hole at a selected location in the first tube, introducing an elongated guide member into the hole, threading the member into the second tube until the second tube contacts the first tube. The second tube is then permanently connected to the first tube and the guide member is then removed to form a T-shaped device. To form the cross-shaped device, a second hole is drilled at a location opposite to the first hole and a guide member is introduced into the second hole as well. A third tube is threaded onto the guide member on the opposite side of the second tube until it contacts the first tube. The third tube is also permanently connected to the first tube and the guide member is removed to yield a device with a cross-shaped configuration.