A chromatography assay device and method for use with whole blood samples utilizing a red blood cell separating agent to aggregate red blood cells and permit plasma or serum to flow by capillary action and a neutralizing agent to neutralize any effects the red blood cell separating agent may have on the device and method. When a total cross sectional area of the heat exchanger tubes at various locations in a flow passage of the cold water is compared, the total area in a downstream location is less than a total area in an upstream location of the flow passage. Thereby, a microstrip antenna with a miniaturized label antenna is accomplished. The magnitude of the light has a range from 0.