Introduction: Blood Cells
Blood contains several different types of cells. Some cells, such as red blood cells, carry oxygen to other cells. Other types of cells, such as white blood cells or leukocytes, provide protection from foreign cells and infectious agents. Cell fragments called platelets provide protection against bleeding. The red blood cells of different animals can have different structures.

»Find out more about blood
Human white blood cell - phagocytosis
Human white blood cells engulf green fluorescent particles.

Elapsed time 5 minutes
A drop of blood was placed on a coverslip with a silicon spacer and diluted with saline solution. The drop was incubated at 37°C for 20 minutes, then red blood cells were washed away. A mixture of saline solution with human serum and opsonized yeast particles was used to cover the remaining cells. Images were taken on an upright inverted microscope with a 40x DIC objective at room temperature using a digital camera. Yeast pariticles have been colored green for visibility.