culture media?

Question

could someone explain what the exact difference between selective media and differential media is?From what i can see they seem to be pretty similar

Answer 1

You are right they are pretty similar but slighlty different.

Differential media allows the grow of one cell type to be more distinguishable over the growth of another. For example if you where to grow bacteria cells with or without the ability to utilize glactasidase. In the presense of glactasidase in the media the cells that can utilize it will turn blue but those that cant will remain white.

Selective media on the other hand allows for the growth one cell type while it suppresses the growth of another. So for example if you where to grow bacteria cells with or without the ability to resist penicillin. In the presence of penicillin in the media the cells with resistance will grow but those without will not.

Hope that helps

Answer 2

Selective media allows specific types of bacteria to grow while killing off others.
It does this by providing optimal conditions for the 'target' bacteria, such as pH and nutritional requirements, thus discouraging growth of other bacteria whose nutritional needs are different.
Differential media has built in characteristics that allow similar types of bacteria to grow but will encourage their appearance to be different.
For example, XLD (Xylose Lysine Deoxycholate) allows growth of the enterics. In my workplace, we use it to differentiate between Salmonella and other enterics such as Citrobacter and Klebsiella.
Because the Citrobacter and the Klebsiella are lactose fermenters, they make the originally red agar turn yellow, where the Salmonella does not. This is due to a phenol-red pH indicator.
In this case, the media is both selective and differential.
I hope this helps.

Answer 3

Selective media use antimicrobial agents to supress all but the organism(s) you are looking for e.g. Prestons media for campylobacter spp.

Differential media contains an indicator to produce a colour reaction in or around the organism(s) colonies you are looking for e.g. Mannitol Salt Agar for differentiating staphylococci.

Differential media may also be selective.

Answer 4

selective only allows certain bacteria to grow
differential is media that allows more than one kind of bacteria to grow, but the types that do grow can be distinguished from each other....
the reason you are confused is because many medias are BOTH selective and differential---that saves money in a clinical lab
an example of a selective and differertial media...MacConkeys
bile salts select for bacteria from the intestines---indicator dyes and lactose tell you which bacteria break down the sugar lactose (milk sugar)

Answer 5

Selective media allows you to kill some cell types while allowing others to live. E.g. say you want to amplify a plasmid containing an ampillicin resistance gene in E. coli. You would transform the E coli with the plasmid and then plate the E coli on slective media containing Ampicclin. The E coli containing the plasmid with the ampicillin resistance gene would grow and non-transformed cells would die. You would SELECT for resistant cells.

Differential media normally contains hormones which encourage non-differentiated cells to differentiate. E.g. you want you plant callus culture to produce shoots and roots so you grow it on differential media containing the appropriate hormones.

Answer 6

As i understand it from practical experience, selective media is used to select for certain types of bacteria eg those which like high pH's, and differential media is for growing several tpes of bacteria with different morphologies. Hope that helps. Feel free to e-mail me if you need more than that

Answer 7

Madia has got 3 faces.because of Its Troika Media.I can see 4. th Face of It.Communication,Information and Propaganda...(sss....Earning Money...)