Classification of blood into four groups (Janský)
Clasificación de la sangre en cuatro grupos (Janský)
- Date
- 1907 · confidence high
- Place
- Prague, Czechia
- Credited to
- Jan Janský
- Field
- Life & health
⚠️ Disputed: the sources disagree.
What was discovered
The Czech neurologist, studying the blood of psychiatric patients, divided human blood into four groups numbered I to IV. His system corresponds to Landsteiner's ABO groups.
Landsteiner described groups A, B and O in 1901 and Decastello and Sturli AB in 1902; Janský (1907) ordered them in four groups independently, before Moss proposed a different numbering in 1910. Janský's numbering prevailed in Europe and Moss's in the United States; Landsteiner's ABO became the universal system.
What it led to
- blood-group-based transfusion, especially in the First World War
- a numbering system used in Central and Eastern Europe
- blood banks