We're smitten with Google's iconic nods to major events in world history, especially when they are science-themed. Today, the Internet giant celebrates the 166th birthday of Danish microbiologist Hans Christian Gram with a cute doodle. Hans is seen dropping a solution on a slide and observing it under a microscope. Born on 13 September 1853, Hans is famous for developing the gram staining method in 1884. It was his pioneering and path-breaking work which helped in the understanding and classification of gram-positive and gram-negative bacteria.

What Led To The Avant-grade Discovery?

While examining lung tissue from patients who had died of pneumonia, Hans had discovered that certain stains were preferentially taken up and retained by bacterial cells. In the first step, he dried a fluid smear on a glass slide over a burner flame and poured Gentian (crystal) violet solution over it. After a water wash, he added Lugol’s solution - potassium triiodide solution, which acted as a mordant to fix the dye if possible. Then he poured ethanol over the slide to wash away the dye. While treating a smear of bacteria with a crystal violet stain, followed by an iodine solution and organic solvent, he found differences in the structure and biochemical function of samples. Certain bacteria like pneumococci retained the gram-positive colour, while other species bleached gram-negative. From Cloning Monkeys to Curiosity Rover Giving Details About Mars, These Are Some of the Biggest Breakthroughs. 

What Did He Conclude?

The Gram-negative bacteria turn into pink colour and gram-positive bacteria turn into violet colour when stained using the Gram stain which is a bacterial staining method. Usually, bacteria that cause tetanus, pneumonia, and food poisoning are types of gram-positive bacteria. The gram staining is a standard staining method that has been used to distinguish bacteria for a long time. The World’s First-in-Human Telerobotic Coronary Intervention Performed in India. 

What Is The Significance of Gram Staining in Medical Diagnosis?

Gram-negative bacteria are often pathogenic and include Escherichia coli, a common cause of food poisoning and Vibrio cholerae, the waterborne pathogen responsible for cholera outbreaks. The pathogenic capability of gram-negative bacteria is caused by their constituent membrane components. From Anti-Vaxxers to AIDS, 10 Deadliest Health Threats of The Year

The lipopolysaccharide endotoxin that resides in the outer membrane can cause a toxic reaction or strong immune response. Gram-negative bacteria that enter the circulatory system may release lipopolysaccharides in large enough amounts to trigger an immune response that is injurious to the host’s organs and tissues. Therefore, the classification of gram-positive and gram-negative bacteria has been key in this kind of diagnosis.

The Danish microbiologist's findings were published in a scholarly journal in 1884 where he 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 also in the hands of other investigators it will turn out to be useful.”

(The above story first appeared on LatestLY on Sep 13, 2019 11:58 AM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).