Thursday, February 28, 2019

Jan Janský

Prof. MUDr. Jan Janský (3 April 1873 - 8 September 1921) discovered blood types.  He was born in Černošice and studied medicine in Prague at Charles University.  During WWI he served as a doctor on the front.  After the war he worked at a military hospital as a neuropsychiatrist.

As a researcher he tried to find a connection between mental diseases and blood diseases but he couldn't find any correlation between the two.  He published a study where he classified blood into four types (I, II, III. IV).  His work went more or less unnoticed but it went on to become the ABO Blood Group System.

In 1930, American Karl Landsteiner won the Nobel Prize for classifying blood into three groups.  But in 1921, the American Medical Commission acknowledged Janský's four-group classification over Landsteiner's.  I don't know why Landsteiner won the Nobel Prize but Janský's classification is still in use today except that now the groups are A, B, AB, and O.

Bronze, Silver, and Gold Janský Medals
Dr. Janský was a proponent of voluntary blood donation.  The Janský Medal is awarded to people for donating blood.  In Czechland, the Bronze medal is awarded for 10 donations, the Silver medal for 20 donations and the Gold medal for 40 donations.  Higher numbers of donations are awarded with eh Golden Cross of the Czech Red Cross (ČČK).

In Slovakia, the Slovak Red Cross awards plaques.  Women earn a Gold Plaque after 30 donations.  Nothing for men.  The Diamond Plaque is awarded to women after 60 donations and to men after 80 donations.

Tajemství krve, The Secret of Blood, is a 1953 Czechoslovak film about Janský's discovery.  Here's the movie trailer that I found out on YouTube.



  1. I am a Czech born immigrant who went on to study and practise Medicine in Australia. When I finish writing up my blog post on Dr Jansky, I will refer back to your post, many thanks
    Dr Joe
    Art and Architecture, mainly

    1. Thanks Dr. Joe. I look forward to reading your post about Dr. Jansky.