50 Blood Tests You Can Carry in Your Pocket

Only the size of a business card, the V-chip may allow clinicians to do up to 50 different blood tests all from a single drop of blood. The V-chip consists of two etched glass plates that are the size of a credit card. Using ELISA (enzyme-linked immunosorbent assay), a sample of serum from the patient's blood is loaded into a well along side three other wells, one containing hydrogen peroxide, another containing the protein, DNA, RNA, or lipid of interest for the test along with the enzyme catalase, and the last well containing a red dye. By slightly shift the glass plates, these 4 wells are brought together, and as the substance of interest comes into contact with the serum the catalase is activated, breaking down the hydrogen peroxide to produce oxygen, pushing the red dye up a column. The amount of oxygen produced can be correlated to the amount of substrate in the patient's blood, meaning the distance traveled by the dye is more or less proportional, resulting in a quick and reasonably accurate bar graph of patient serum values. The V-chip is still in development, and the researchers hope to make the device more user friendly, simple, and robust.

http://phys.org/news/2012-12-pocket-blood.html#jCp
http://www.nature.com/ncomms/journal/v3/n12/full/ncomms2292.html