Streaking an Agar Plate

How to streak an agar plate with bacteria - to isolate single bacterial colonies for identification

Category:

Howto & Style

Tags:

• bacteria
• streaking
• isolation
• colony
• agar
• plate

[59arkady]

Please; why are you touching the sterilized loop to the agar (post inoculation) before you start your streak?

Thank you.

[cegodsey]

You can wait several seconds to make sure the loop is cool, or you can touch it to the agar to cool it.

[cegodsey]

Actually, this is the method used by the US Navy.

[Kabulay]

Its far better to make right strokes..! 5-5-5-5..!

And you are not sterilizing proberly, you should hold the loop more in the flame, not just the tip!

[cegodsey]

whatever! Stroke this!

[nobushino]

LOL!! Lot of angry people out here, with no videos of their own to show how to properly do the procedure. You people love to criticize others by calling them idiots or dumbasses. Is it really necessary? We can say our opinions in a good and civilized manner. So why not post your own videos?

[Mxsmanic]

I'm confused: if you sterilize the loop before you touch it to the agar plate, doesn't that mean that there will be no bacteria on the plate? Where is the bacteria coming from?

[The0leon]

@59arkady to cool down the wire loop so that it will not kill the bacteria

[robin182]

Vebzther - it depends on your standard. Based on water ana colony count below 0-500 is still acceptable.

[82Horror]

touching the agar with the loop just to cool it that's all

[Vebzther]

Pls answer me guys I really need help. I am asked to perform total plate count/aerobic plate count on a pasteurized fruit juice. I need to prove that the product is safe to drink. My teacher told me to make 0, -1, and -2 dilution. If I want to prove that my product is safe thru microbiological reasons does that mean that all my plates should have 0 count? Is it fine to have count at the range of 30-300? Or does 30-300 count mean that my juice product is not safe to consume? TY!

[PatterGuitsIt]

Too bad, no audio but great video.

[hamzie11]

Lol this isnt how you inoculate.

And no touching the agar is not a way to cool the tip, it is a way to make sure it still isnt hot.

and you definitely dont cut it near the centre of the agar and then streak over it

[JaCalsGal]

@cegodsey  lol!

[riool]

Bad example. He is not wearing a white coat and the lid of the petridish should be with the open side on the table. In this way you do not get any dust and bacteria from your white coat (clothes) in the lid.