Blood serum is used for many types of analyses and may provide useful insights into a state of health of a person of whom the blood serum belongs. Blood serum needs to be separated from blood, which in turn has to be collected from a person. A device is provided in which a strip of lateral flow paper may be placed. When a sample of blood is provided on a receiving section of the strip of lateral flow paper, due to capillary action, the blood is transported through the lateral flow paper. While being transported, the lateral flow paper acts a sieve in which amongst others red blood cells are trapped. Blood serum, and many constituents it holds, is not sieved and is therefor separated from the blood. The blood serum on the lateral flow paper may be used for analysis when dissolved in an extraction liquid.
