Thread: Gram negative/positive stain without access to infected material?

Hello I am new here. What kind of tissue could I use for a gram negative/positive stain without having access to infected tissue? I know slim jim's have both positive and negative bacteria and I believe hot dogs. Is there some way of infecting meat, like steak, maybe let it rot? I know about buying tissue slides and blocks for this purpose but I am flat broke and can not do this.
Thanks

Ehm, you can grow your own bacteria yes. Use a bucket, add grinded down meat (really fine), add sugar, a knifetip of salt, 1 liter of water, mix thoroughly.. And you have your home grown bacteria broth. Most growable bacteria will grow in here.

If you want a gram negative strain (E.coli), you should keep the oxygen level at intermediate, not to much not to few. And do not incubate long (16 hours), but at 37 celcius.

For gram positive strain, staphylococcus, add a lot more salt (1 or 2 spoons), it's the selective part of the medium, also keep the temperature at 25-30 celcius to slow other bacteria down. Most will not grow well in here but staphylococcus does. Incubate for a longer period, (36-48H)

If you put anything after this period in any of these buckets, it'll be infected..

That's great! Thank you very much.