Bacterial Cell Wall Composition Almost all bacteria have cell walls surrounding the cell membranes. This cell wall helps to do important functions, like confer cell shape, and protect the cell from lysis when in low solute environments. There are three classifications used in describing cell walls: Gram Positive (Gram+), Gram Negative (Gram-) and Acid-Fast. These membranes share a common part in their structure, however--an interlocked layer of peptidoglycan. Peptidoglycan is a molecular complex made from …showed first 75 words of 1405 total…

…showed last 75 words of 1405 total…is the most critical and also the one most affected by technical variations in timing and reagents. 4.Flood with safranin (pink color) - 10 seconds. (Wash with water). Air dry, or blot with absorbent paper. Results As shown below, organisms that retain the violet-iodine complexes after washing in ethanol stain purple and are termed Gram-positive, those that lose this complex stain red from the safranin counterstain are termed Gram-negative. Typical Gram stain Gram positive Gram negative