A new lab recruit performs their first Gram stain on a slide containing both G(+) and G(-) organisms. After finishing the staining, they realize that they misread the labels on the crystal violet and Gram’s iodine vials. They accidentally used Gram’s iodine in place of crystal violet, and vice versa. Explain what you expect the recruit to see under the microscope, and explain why they see it.
Microscopic examination
The analysis of minute organisms, cellular organization of any biological structure, and composition of body fluids with the help of a microscope is known as microscopic examination. The magnification of specimens or samples under study helps in attaining a clearer picture of it.
Gram Staining
Named after Hans Christian Gram, a Danish bacteriologist, Gram stain is one of the most powerful staining techniques within microbiology. This technique was introduced in 1882 to identify pneumonia-causing organisms. The Gram staining technique uses crystal violet or methylene blue as primary staining colors to distinguish gram-positive from gram-negative organisms. Under a microscope, the gram-positive organisms appear purple-brown, retaining the primary color. Gram-negative organisms appear pink or red as they do not acquire the color of the primary stain.
A new lab recruit performs their first
Gram staining is a common technique used to differentiate between gram positive and gram negative groups of bacteria hence it is an differential stain.
Gram staining is based on the ability of bacterial cell to retain crystal violet dye during solvent treatment.
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