Abstract: Disclosed herein is a sample collection device for an aqueous fluid, such as whole blood, serum, plasma and urine. The device comprises a cartridge body defining an elongate sample collection passage that has open ends. The passage is arranged to draw the fluid into the passage by capillary action. The passage is provided along a portion of its length with a sample metering stop in the form of a hydrophobic coating arranged to prevent flow of the fluid by capillary action thereacross. A sample receiving portion of the passage extending between a collection end and the metering stop is non-linear, and preferably defines a pair of straight limbs connected by a bend. By providing a non-linear passage in this way, the maximum gravitational force which can act on the collected sample is reduced as compared to a conventional linear passage, thereby reducing the tendency of the sample to leak from the device and potentially avoiding the need for one or both ends of the passage to be sealed.

Abstract: This invention relates to a capillary channel comprising a first pair of opposing walls defining a width and a second pair of opposing walls defining a depth, wherein the channel has an aspect ratio of 10-100 defined as the ratio of the width to the depth of the channel and wherein an internal surface of at least one of the second pair of opposing walls is roughened. The capillary channel is preferably incorporated into a sensor.