Blood-letting prop Our Scalpel Blood FX Prop is made from a real medical scalpel that has been modified so that it's safe to handle. The blade has been replaced with a realistic prop blade so that it is safe to touch. A small dropper is mounted to the side of the instrument. All you need to do is fill the dropper with blood and the prop is ready to use. Just depress the dropper slowly while dragging the blade across the skin. This will create the illusion of a fresh incision on the skin. A one-ounce bottle of blood included.