Final answer:
The Gram stain is a differential staining procedure distinguishing between gram-positive (purple) and gram-negative (pink) bacteria based on cell wall structure. Acid-fast staining distinguishes certain gram-positive bacteria with waxy cell walls. These techniques are crucial for bacterial identification and classification.
Step-by-step explanation:
The Gram stain procedure is a differential staining technique that classifies bacteria based on their cell wall structure and is used to differentiate between gram-positive and gram-negative bacteria. In this method, bacteria that retain the primary stain (crystal violet) after the decolorizing step are classified as gram-positive and appear purple due to the thick peptidoglycan layer in their cell walls. Conversely, gram-negative bacteria have a thin peptidoglycan layer and do not retain the crystal violet, appearing light red/pink after being counterstained with safranin.
Acid-fast staining, another differential staining technique, distinguishes between types of gram-positive cells, those with waxy mycolic acids in their cell walls and those without. This technique uses carbolfuchsin as the primary stain, which is retained by acid-fast cells even after a decolorizing agent is applied. These staining patterns are essential for identifying and classifying bacteria in medical and research settings.