Blood many invertebrates, these oxygen-carrying proteins are freely soluble in the blood; in vertebrates they are contained in specialized red blood cells, allowing for a higher concentration of respiratory pigments without increasing viscosity or damaging blood filtering organs like the kidneys. Giant tube worms have unusual hemoglobins that allow them to live in extraordinary environments. These hemoglobins also carry sulfides normally fatal in other animals. The coloring matter of blood (hemochrome) is largely due to the protein in the blood responsible for oxygen transport. Different groups of organisms use different proteins. Hemoglobin is the principal determinant of the color of blood
Genetically engineered blood protein and a substance of choice, such as a small-molecule therapeutic agent or an antibody. The modifications leave the cells and their surfaces otherwise intact. One application is to engineer red blood cells into drug-delivery vehicles. Mature red cells carry no genetic material, potentially presenting fewer safety risks than other gene and cell therapies. Human red blood cells circulate for as long as four months, meaning they could potentially form the basis of long-term therapies. The cells move throughout body via the bloodstream and are unnoticed by the immune system. Genetically engineered blood Genetically engineered blood is blood that has