2005/10/15 by Richard Coico · 3 citations
Biochemistry, Genetics and Molecular Biology · #Molecular Biology Techniques and Applications
paper · doi:10.1002/9780471729259.mca03cs00
openalex publication_date 2005/10/15 · openalex created_date 2019/09/26 · openalex updated_date 2026/06/09
Named after Hans Christian Gram who developed the method in 1884, the Gram stain allows one to distinguish between Gram-positive and Gram-negative bacteria on the basis of differential staining with a crystal violet-iodine complex and a safranin counterstain. The cell walls of Gram-positive organisms retain this complex after treatment with alcohol and appear purple, whereas gram-negative organisms decolorize following such treatment and appear pink. The method described here is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures.