Search engine giant Google on Friday marked the 166th birth anniversary of celebrated Danish bacteriologist Hans Christian Gram with a special doodle tribute that showed him working and researching in his laboratory. Gram is best known for his development of the Gram stain, a technique to identify and classify different types of bacteria. Gram's namesake staining technique, one of the groundbreaking discoveries in the study of microbiology, is being used till the date.
Born on September 13, 1853, in the Danish capital of Copenhagen, Gram was the son of Frederik Terkel Julius Gram, a professor of jurisprudence, and Louise Christiane Roulund. Initially, he studied at the University of Copenhagen and was an assistant in botany to the zoologist Japetus Steenstrup. His study of plants introduced him to the fundamentals of pharmacognosy and the use of the microscope.
In 1878, Gram entered medical school and completed his graduation in 1883. He travelled throughout Europe between 1878 and 1885. This was the time when he developed the evergreen Gram stain technique that gave him an international reputation.
The stain technique, which was invented to make bacteria more visible under microscope, later played a major role in classifying bacteria. The study was first appeared in a scholarly journal in 1884, where Gram remarked, "I have therefore published the method, although I am aware that as yet it is very defective and imperfect, but it is hoped that also in the hands of other investigators it will turn out to be useful".
A Gram stain is made using a primary stain of crystal violet and a counterstain of safranin. Bacteria that turn purple when stained are called 'Gram-positive', while those that turn red when counterstained are called 'Gram-negative'.
Apart from the staining technique, some of his other works include the study of red blood cells in men and the recognizing macrocytes as the characteristic of pernicious anaemia.
Gram also served as a professor of medicine at the University of Copenhagen and published four volumes of clinical lectures which became widely used in Denmark. He retired from the University of Copenhagen in 1923 and died in 1938 at the age of 85.