Detection of hemolysis using a chromatographic assay device

A chromatographic assay device for detecting presence of free hemoglobin in a liquid biological sample, the device comprising:

• a sample application pad for application of the liquid biological sample, wherein the sample application pad is formed of a first layer of a prefiltration material and a second layer of a filtration material which is different than the prefiltration material, wherein the sample application pad is porous to plasma and the free hemoglobin and not porous to red blood cells so that red blood cells present in the liquid biological sample are retained within the first and second layers of the sample application pad and are thereby prevented from flowing there through;
• and
• a chromatographic detection pad which defines a path for capillary fluid flow, the chromatographic detection pad having a first end portion that is in fluidic contact with the sample application pad and that forms a sample application site on the chromatographic detection pad, the chromatographic detection pad further having a detection site spaced apart from the sample application site;
• wherein the free hemoglobin flows through the sample application pad into the chromatographic detection pad and from the sample application site to the detection site and is detectable via a color change at the detection site.