False-colour scanning electron micrograph (SEM) of human red blood cells (biconcave erythrocytes), which function in the transport of oxygen to the cells and tissues of the body. Mature erythrocytes are biconcave discs (lacking in a nucleus), & approximately 7.5 microns in diameter. The biconcave shape is an adaptation for maximum surface area, over which the exchange of oxygen and carbon dioxide may take place. Essentially, they are non-motile bags of haemoglobin (the blood's oxygen-carrying molecule) that are flexible & able to permeate the smallest capillaries. Magnification: X 3945 at 35mm size. Coloured red. Original is BW print P242/029.
Model release not required. Property release not required.