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Know Every thing About Hans Christian Gram

Hans Christian Joachim Gram

In this Page You Will  Know Everything About Hans christian Joachim Gram


   Know Everything About this Man

13 September 1853
Copenhagen, Denmark
14 November 1938 (aged 85)
Copenhagen, Denmark
Known for
Inventing the Gram stain

Gram was born on September 13, 1853, in Denmark’s Copenhagen. Gram is best known for pioneering the method of the Gram stain to identify bacteria.

The Danish microbiologist earned an M.D. from the University of Copenhagen in 1878. He then traveled through Europe between 1883 to 1885 studying pharmacology and bacteriology.

It was in 1884, while working in the lab of German microbiologist Karl Friedländer in Berlin, that he devised his famous staining technique that is now still used to identify and classify different types of bacteria. He followed the method of Paul Ehrlich, using aniline-water and gentian violet solution.

Gram's initial work concerned the study of red blood cells in men. He was among the first to recognize that macrocytes were characteristic of pernicious anemia.

Gram was appointed a professor of medicine at the University of Copenhagen in 1900. As a professor, he 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.


  Don't Miss Out These Important Questions?

1. What does Gram stain positive mean?

Gram-positive: Gram-positive bacteria retain the color of the crystal violet stain in the Gram stain. This is characteristic of bacteria that have a cell wall composed of a thick layer of a particular substance (called peptidologlycan). ... Gram's method helps distinguish between different types of bacteria.

2. What is the difference between a gram positive and gram negative bacteria?

Gram positive bacteria will stain purple because of their thick peptidoglycan cell wall. Gram negative cell walls contain a thin peptidoglycan layer (without teichoic acids) that is surrounded by a thick plasma membrane.

3. What is the procedure for Gram staining?

There are four basic steps of the Gram stain:
Applying a primary stain (crystal violet) to a heat-fixed smear of a bacterial culture. ...
The addition of iodide, which binds to crystal violet and traps it in the cell.
Rapid decolorization with ethanol or acetone.
Counterstaining with safranin.

4. Is Gram positive or negative worse?

As a rule of thumb (which has exceptions), Gram-negative bacteria are more dangerous as disease organisms, because their outer membrane is often hidden by a capsule or slime layer which hides the antigens of the cell and so acts as "camouflage" - the human body recognises a foreign body by its antigens

5. Why is Gram staining used?

Gram staining is a common technique used to differentiate two large groups of bacteria based on their different cell wall constituents. The Gram stain procedure distinguishes between Gram positive and Gram negative groups by coloring these cells red or violet

6. What diseases are caused by Gram positive bacteria?

Gram-positive cocci cause certain infections, including the following:
Pneumococcal infections.
Staphylococcal aureus infections.
Streptococcal infections.
Toxic shock syndrome.

7. What kills Gram positive bacteria?

Gram-positive bacteria, those species with peptidoglycan outer layers, are easier to kill - their thick peptidoglycan layer absorbs antibiotics and cleaning products easily.

8. Why Gram stain test is done?

A Gram stain is a laboratory procedure used to detect the presence of bacteria and sometimes fungi in a sample taken from the site of a suspected infection. It gives relatively quick results as to whether bacteria or fungi are present and, if so, the general type(s)

9. Why 95 Ethanol is used in Gram staining?

Either acetone or ethyl alcohol can be used as the decolorizing agent. The alcohol dissolves lipids found in the outer cell membrane of Gram-negative bacteria, allowing the crystal violet-iodine complex to leak out of the thinner peptidoglycan layer.

10. Why Safranin is used in Gram staining?

Safranin is used as counter stain in Gram staining procedure to differentiate between gram positive and gram negative organisms. ... In practice,a thin smear of bacterial cells is stained with crystal violet, then treated with an iodine containing mordant to increase the binding of primary stain (2)

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