A device is constructed so as to define a capillary channel that draws a body fluid form a proximal portion of the capillary channel toward a distal portion. A counterbore defining a &ldquo；ledge&rdquo； not substantially normal to the center line of channel causes the meniscus of body fluid to be &ldquo；biased&rdquo； into a non-radially-symmetric shape. In one example, the bias draws the body fluid toward a testing element that is set into a groove in the main body of the device. In another example, hydrophilic and/or hydrophobic regions are created on or in device to produce the biasing effect. In certain configurations, device requires less blood to be drawn into the capillary channel for a successful test than if the biasing effect were not created.
