Home Forum Dictionary Articles Tutorials Books Directory Share your work


Edit page | Page history | Printable version

Dictionary » G » Gram-negative

Gram-negative

Gram-negative

(Science: microbiology) a common class of bacteria normally found in the gastrointestinal tract that can be responsible for disease in man (sepsis).

bacteria are considered to be gram-negative because of their characteristic staining properties under the microscope, where they either do not stain or are decolourised by alcohol during grams method of staining.

this is a primary characteristic of bacteria that have a cell wall composed of a thin layer of peptidoglycan covered by an outer membrane of lipoprotein and lipopolysaccharide containing endotoxin.

The gram staining characteristics of bacteria have resulted in an important classification system for the identification of bacteria.

See: gram-positive


Please contribute to this project, if you have more information about this term feel free to edit this page



Results from our forum


Please help us I.D. this micro-organism

... you're using? Third, you say you found an organism living in a human. Have you taken any steps to identify it's domain? Any staining at all? (ie, gram +/- or nuclear staining, etc..) It's near impossible to identify an organism with the information you provided.

See entire post
by jyaron
Sun Aug 09, 2009 5:10 pm
 
Forum: Microbiology
Topic: Please help us I.D. this micro-organism
Replies: 4
Views: 168

Not getting lower molecular weight bands in SDS-PAGE

... i am getting distinct bands at higher molecular weight region but not getting anything below 35 kD region. i'm approximately loading 25 micro gram of protein. i have confirmed the observation by immunobloting the membrane with higher (VDAC-1) and lower molecular weight (COX-IV) proteins. Could ...

See entire post
by writoban
Wed Aug 05, 2009 12:52 pm
 
Forum: Molecular Biology
Topic: Not getting lower molecular weight bands in SDS-PAGE
Replies: 1
Views: 86

Methods Identifying Unknown Bacteria?

... this is a good way. Although I would disagree with the use of antibiotics as they are not species specific. Although the microscopic observation (gram, shape, capsule...) is usually done after the bacteria has been grown so you should know by then if it is aerobic or not. Then a group of selective ...

See entire post
by canalon
Wed Jul 22, 2009 4:27 pm
 
Forum: Microbiology
Topic: Methods Identifying Unknown Bacteria?
Replies: 5
Views: 224

Methods Identifying Unknown Bacteria?

Isn't the first thing to do is a Gram stain? And then find out if it is anaerobic, aerobic, or facultative? then look at it under a microscope for its shape? what about the media that it can grow on? put different antibiotics in the media ...

See entire post
by kolean
Wed Jul 22, 2009 12:42 pm
 
Forum: Microbiology
Topic: Methods Identifying Unknown Bacteria?
Replies: 5
Views: 224

help identify unknow species

hi, i really need help identifying unknown species. Can anyone help,please. Here is what I have done in lab and here are my results: Gram (-) rod strict aerobic MacConey : Gram-,Lac- motile (+) endospore(-) oxidase(+) catalase(-) H2S(-) reduction of nitrate and nitrite(-) glucose fermentation ...

See entire post
by 198839
Sat Jul 11, 2009 12:26 am
 
Forum: Microbiology
Topic: help identify unknow species
Replies: 2
Views: 154
View all matching forum results

This page was last modified 21:16, 3 October 2005. This page has been accessed 4,324 times. 
What links here | Related changes | Permanent link