Figure 1

(a) An unused surgical cotton gauze (left), unused polyurethane sheet (center), and polyurethane sheet subjected to the blood-soak and water-rinse procedure 10 times (right). Note that the polyurethane sheet retains sufficient whiteness even after repeated use. Four drops (0.1 cc each) of blood were dropped at 2-cm intervals on a new surgical cotton gauze (b) and a polyurethane sheet that was used 10 times (c). Note that the spread of the blood is lesser on the polyurethane sheet.