Gram's Method

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Gram’s Method


a method for the differential staining of bacteria, proposed in 1884 by the Danish physician H. C. Gram.

In Gram’s method the bacteria are stained with basic dyes, including crystal or methyl violet, which are then fixed in an iodine solution. After rinsing the dyed preparation in alcohol some types of bacteria remain thoroughly stained (the so-called gram-positive bacteria), and others (gram-negative) are decolorized. Such a division is of great importance in the classification of bacteria and in the microbiological diagnosis of infectious diseases.

References in periodicals archive ?
In one case of acute bacterial meningitis, Gram staining showed gram-positive diplococci and the UF-100 bacterial count was high, whereas the culture remained negative after 7 days, probably because of antibiotic treatment before lumbar puncture.
The possibility of nutritionally variant streptococci (NVS) should be considered when gram-positive cocci or bacilli are seen on Gram staining, but the cocci/bacilli grow poorly on non-supplemented media.
Gram staining of blood-free supernatants from all positive cultures was interpreted as showing a homogeneous smear of gram-positive diplococci and was used as the inoculum of Sceptor gram-positive Breakpoint/ID panels (Becton Dickinson, Franklin Lakes, NJ).
Variables influencing results, and the precise definition of seeps in Gram staining as a means of standardizing the results obtained.
Contrary to standard texts, the purple dye called crystal violet, a main ingredient in gram staining, does not actually enter bacterial cells, researchers report online April 27 in ACS Chemical Biology.
sibiricum as a pathogen and not a contaminant because it was the only organism isolated, and Gram staining of the exudate revealed leukocytes.
Table 1: Gram staining and solubilization index of potential phosphate solubilizing bacteria in National Botanical Research Institute's phosphate (NBRIP) growth medium.
We limit this discussion to six desired features, summarized in the priority shown from the input of more than 50 high-volume gram staining labs:
Outside of regular duty hours, BC samples that turned positive for microbial growth were immediately processed for Gram staining and cultivated for later biochemical bacterial identification (confirmation of MALDI-TOF MS results), antibiotic susceptibility testing, and MALDI-TOF MS (Fig.
Ventana), a member of the Roche Group, today announced the global launch of the VENTANA Gram Staining Kit[sup.
There is no precise criteria for interpreting the normal or pathogenic, and using conventional polymerase chain method it can only prove the presence of microorganism in the vagina, but not the number of colony forming units, while Gram staining microscopy is simple vaginal flora diagnostic techniques that have established criteria for diagnostic the pathology.
Gram staining of the smears was performed as described previously (19).