Article: The treatments below are potentially strong enough to damage or discolor your carpet. Always test them on a small, hidden spot of your carpet first. Let them sit for at least 15 minutes, or until dry, then check for damage. Silk and wool carpets are notoriously easy to damage, and you may not even want to risk a corner. Consider hiring a professional instead. Scrape a butter knife across the carpet fibers to remove flecks of dried blood. This gives you a head start on heavy spills, but won't do the trick by itself. This is not recommended for valuable carpets. This chemical breaks down proteins in the blood stain, making it easier to remove. Mix this with an equal amount of cold water, then dab onto the stain. Let sit 15–30 minutes, then blot with a clean towel. Rinse off with a drop of liquid detergent mixed into cold water.  Avoid flavored meat tenderizer, which can create new stains. This may break down fibers in wool or silk carpets, since these also contain animal protein. Hydrogen peroxide lightens the color of your carpet fibers, hiding the stain. Wet the stain with 3% hydrogen peroxide. Let dry in a well-lit room, and it will break down with no further need for rinsing.  This is a risky method for carpets with dark or vivid colors, but much safer than using bleach. Most drugstores sell 3% hydrogen peroxide. If your bottle is more concentrated, dilute some to 3% strength. (For instance, mix one part 9% hydrogen peroxide with two parts cold water.) Ammonia is highly effective, but may discolor the carpet and damage wool or silk. While you can use the ammonia treatment by itself, it is most effective following ordinary detergent:  Mix 2 teaspoons (10 mL) shampoo or liquid dishwashing detergent in 1 cup (240 mL) water. Spray on carpet and let sit for five minutes. Mix 1 tablespoon (15 mL) household ammonia in 1 cup (240 mL) room temperature water. Take care not to inhale ammonia fumes. Blot shampoo dry, then spray on ammonia. Let sit five minutes, then blot dry again. Spray on water and blot dry, to rinse. Commercial enzyme cleaners break down the complex chemicals found in blood and other organic stains. Apply according to label instructions, typically by spraying over the stain, letting it sit, then blotting dry.  These are often sold as pet urine removers. Some environmentally friendly laundry detergents contain enzyme cleaners, but use these only if you can't find a product designed for carpets.  These products may not work as well at cold or very hot temperatures. Do not apply to wool or silk carpets, since the cleaner may break them down along with the blood. Once the stain is removed, set up an electric fan blowing over the wet area, or open the windows and doors to create a breeze. This speeds up drying, which reduces the chance of hidden blood in the backing rising to the surface. Your carpet fiber may feel stiff or crusty once it dries. A quick use of a vacuum or carpet brush should restore it to its original feel.

What is a summary?
Test each treatment on a hidden area first. Brush with a dull knife (optional). Apply unflavored meat tenderizer. Wet the tufts with hydrogen peroxide. Soak in shampoo, then ammonia. Use an enzyme cleaner. Dry the carpet in an area with good air flow. Vacuum or brush the carpet.