What are blood types?
Blood types are determined by antigens on the surface of red blood cells. The ABO system classifies blood as A, B, AB, or O.
Educational resources
Learn about blood science
Explore the science behind blood types and discover why this knowledge is essential in medicine.
Key concepts
Fundamental knowledge about blood science and immunology.
The Rh factor
The Rh factor (positive or negative) is another important blood group system, determined by the presence or absence of the Rh antigen.
Antigens and antibodies
Antigens trigger immune responses, while antibodies are proteins that recognize and bind to specific antigens.
Why blood typing matters
Blood typing is critical for safe blood transfusions, organ transplants, and understanding certain medical conditions.
Additional resources
Trusted sources to expand your understanding.
American Red Cross
Blood donation and typing information
Khan Academy
Free lessons on immunology
NIH Blood Resources
Research and educational materials