Red blood cells (erythrocytes). This image of human red blood cells obtained by scanning electron microscopy, revealing their characteristic biconcave shape.
Biological Process: Gas transport
The scanning electron microscope scans the specimen with a finely focused electron beam and records the number of electrons emitted at each point in the scan as a grey level in the image, with low levels corresponding to few emitted electrons and high levels corresponding to many emitted. Specimens are usually coated with a thin layer of metal to improve conductivity and increase the efficiency of secondary electron emission.
Author: Tina Carvalho
Source: The Cell: An Image Library
