And in this method, we also use a specific property of proteins. So many proteins inside our body have a specific high affinity to some type of molecule. And the general example of these proteins are enzymes. So enzymes are these proteins found inside our body that bind to specific substrate molecules and accelerate the reaction, basically increase the rate at which that reaction actually takes place. Enzymes are biological catalysts, and we have many different types of enzymes in our body. For example, just in our immune system alone, we have many, many, many proteins.