Final answer:
The Gram staining process increases the permeability of the lipid-rich outer membrane in Gram-negative bacteria due to the use of a decolorizer, leading to the primary stain being washed out. This differentiates Gram-negative from Gram-positive bacteria based on their cell wall properties, with Gram-positive retaining the primary stain.
Step-by-step explanation:
The correct option is B:
The staining process that causes increased permeability of the lipid-rich cell wall due to decolorizer, resulting in the primary stain washing out, is b) Gram staining.
The Gram stain procedure is a differential staining technique that distinguishes bacteria based on their cell wall structure. During the Gram staining process, cells are initially stained with crystal violet, followed by the application of iodine, which acts as a mordant. The critical step is the application of alcohol, a decolorizer, which increases the permeability of the lipid-rich outer membrane of Gram-negative bacteria. Due to this increased permeability, the primary stain is washed out of Gram-negative cells, whereas Gram-positive bacteria, with their thicker peptidoglycan layer, retain the crystal violet stain. Subsequent counterstaining with safranin colors the decolorized Gram-negative cells pink, contrasting with the purple color of Gram-positive cells. Imperfections in cell wall structure, as well as improper application of the decolorizer, can affect the accuracy of this staining technique. It is important to note that only fresh bacterial cultures should be used for Gram staining to get reliable results.