Some laboratories use safranin as a counterstain however, basic fuchsin stains gram-negative organisms more intensely than safranin. The final step in gram staining is to use basic fuchsin stain to give decolorized gram-negative bacteria pink color for easier identification. The length of decolorization is a critical step in gram staining as prolonged exposure to a decolorizing agent can remove all the stains from both types of bacteria. In contrast, solvent dehydrates the gram-positive cell walls with the closure of pores preventing diffusion of violet-iodine complex, and thus, bacteria remain stained. With the dissolution of the lipid layer, gram negatives lose the primary stain. Gram-positive bacteria stain blue when this stain is applied to them. Initially, all bacteria take up crystal violet dye however, with the use of solvent, the lipid layer from gram-negative organisms is dissolved. Gram-positive bacteria are classified by the color they turn after a chemical called Gram stain is applied to them. The Gram stain reaction is based on the difference in the chemical composition of bacterial cell walls. Gram-positive microorganisms have higher peptidoglycan content, whereas gram-negative organisms have higher lipid content. shows gram-positive and gram-negative stained cells. The basic principle of gram staining involves the ability of the bacterial cell wall to retain the crystal violet dye during solvent treatment.

Subsequently, a decolorizer, often solvent of ethanol and acetone, is used to remove the dye. The next step, also known as fixing the dye, involves using iodine to form crystal violet- iodine complex to prevent easy removal of dye. The first step in gram staining is the use of crystal violet dye for the slide's initial staining. The organisms that do not take up primary stain appear red under a microscope and are Gram-negative organisms. The term for organisms that retain the primary color and appear purple-brown under a microscope is Gram-positive organisms. Counterstain, which is usually positively charged safranin or basic fuchsine, is applied last to give decolorized gram-negative bacteria a pink or red color. Often the first test performed, gram staining involves the use of crystal violet or methylene blue as the primary color. It gets its name from the Danish bacteriologist Hans Christian Gram who first introduced it in 1882, mainly to identify organisms causing pneumonia. The Gram staining is one of the most crucial staining techniques in microbiology. Discovered in 1884, Gram stain technique has proven to be one of the most useful phenotypic classification systems through which bacteria can be identified. read more, wound or surgical site infections, and meningitis Acute Bacterial Meningitis Acute bacterial meningitis is rapidly developing inflammation of the layers of tissue that cover the brain and spinal cord (meninges) and of the fluid-filled space between the meninges (subarachnoid. Bacteremia may result from ordinary activities (such as vigorous toothbrushing), dental or medical procedures, or from infections. Bacteria are traditionally classified based on their Gram-staining response into the gram-positive and gram-negative bacteria. read more, bloodstream infections Bacteremia Bacteremia is the presence of bacteria in the bloodstream. The tube that carries urine from the bladder out of the body (urethra) contains no bacteria. read more (inflammation of the membrane that lines the abdominal cavity), urinary tract infections Overview of Urinary Tract Infections (UTIs) In healthy people, urine in the bladder is sterile-no bacteria or other infectious organisms are present. The pain may be the only sign of the need for surgery. The counter stain, safranin, is used to color the. The dye rinses out in gram negative cells. Severe abdominal pain that comes on quickly, however, almost always indicates a significant problem. Gram positive cells will retain the dye complex and remain purple. Hans Christian Gram developed the staining method in 1884. read more, peritonitis Peritonitis Abdominal pain is common and often minor. Gram-positive bacteria are bacteria classified by the color they turn in the staining method. Pneumonia is one of the most common causes of death worldwide. Purpose of the Gram Staining Technique The results of the Gram stain are viewed using light microscopy. Gram-negative bacteria can cause many serious infections, such as pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. If the staining procedure is performed correctly, gram-positive bacteria will be purple, while gram-negative bacteria will be pink.

Gram positive vs gram negative color