Today Google dedicated its doodle to Hans Christian Gram, on his 166th birth anniversary. Gram was a Danish bacteriologist born on 13th September 1853. He developed a technique for identifying and classifying bacteria which is known as Gram stain technique. This technique is still extensively used, even after a centenary.
Gram studied at Copehagen University and later started to work in the field of bacteriology and pharmacology. It was during this period when he worked in Berlin laboratory, he discovered 'Gram stain'. This process consist of treating a bacteria with a violet dye, later rinsing it with iodine and an organic solvent. Bacteria with a thick cell wall (outer membrane) remain purple concludes as Gram positive. Whereas one which has thinner cell wall and do not pertain the stain are termed as gram negative.
In 1884, he published his scientific journal which included all of his scientific inventions and wrote, "I have therefore published the method, although I am aware that as yet it is very defective and imperfect; but it is hoped that in the hands of other investigators it will turn out to be useful." Gram died in 1938 leaving behind his exceptional contribution.