Use Mac Conkey agar plates where u can get only GNB.

well..try to subculture on appropriate agar plate and obtain an isolated colony of the Gram -ve bacteria (after confirmation through staining). Pick that colony and inoculate in broth medium to get the pure culture..but do it aseptically to avoid any contamination.

Use Mac Conkey agar plates where u can get only GNB.

use selective agar for Gram -ve bacteria...n then isolate the single colony followed by enrichment in d broth..b4 that do perform some Gram -ve confirmation testing..

Thank u sir

It depends on what bacteria you need to isolate. There are so many G- and +. McConkey will not get so many G-ves.

It depends on the genus you are dealing with. MacConkey works well for the Enterobacteriaceae, Vibrios, Aeromonas, Pseudomonas and some other Gram-negative bacteria that grow on it. Usually Gram-positive bacteria are vancomycin-susceptible and Gram-negatives are vancomycin-resistant. For highly fastidious and antibiotic susceptible Gram-negatives i.e. members of the Pasteurellaceae, Francisella, Brucella, you can either use antibiotics that they are resistant to or consider increasing the agar concentration of the medium. If the Gram-negative is mixed in a broth - try to get it out by dilution plating onto agar.

Than x to all.I got the culture by dilution plating on media with different ph and nacl conc.