The lysis or the breaking open of red blood cell (erythrocyte) causing the release of hemoglobin into the surrounding fluid.
Hemolysis has several causes: examples are exposure of erythrocytes to toxins and poisons, bacterial haemolysins, immune reactions like specific complement-fixing antibodies, hypotonicity, alteration of temperature, treatments such as hemodialysis, etc.
In microbiology, the hemolytic reactions of certain microorganisms such as streptococci on blood agar plates can be used to identify or classify them. For instance, Streptococcus pneumoniae forms alpha hemolysis, Streptococcus pyogenes forms beta hemolysis, and Enterococcus faecalis displays gamma hemolysis on blood agar plates.
Word origin: from the Greek hemo-, meaning blood + –lysis, meaning to break open.
Related forms: hemolytic (adjective).
Also spelled as: haemolysis.
See also: hemolysin.