HANS CHRISTIAN JOACHIM GRAM

About: 

• Hans Christian Joachim Gram was born in 1853, in Denmark’s Copenhagen.
  
  
• The Danish microbiologist is best known for pioneering the method of the Gram stain to identify bacteria, which is still widely used.
  
  

Gram staining method:

• Staining is an auxiliary technique used in microscopic techniques to enhance the clarity of the microscopic image. The most widely used staining procedure is the Gram stain.
  
  
• Gram staining is a differential staining technique that differentiates bacteria into two groups: gram-positives and gram-negatives. The procedure is based on the ability of microorganisms to retain colour of the stains.
  
  
• Gram-negative bacteria are decolorized by the alcohol, losing the colour of the primary stain, purple. Gram-positive bacteria are not decolorized by alcohol and will remain as purple.
  
  
• Importance: The Gram stain is a very important preliminary step in the initial characterization and classification of bacteria. It also enables the bacteria to be examined using a light microscope.