Urgent agar related advice needed!!

[duckduckgoose]

Hi, I was wondering if the instructions on the following link are accurate and, if the beef stuff mentioned is just beef stock? Thanks very much! http://www.newton.dep.anl.gov/askasci/mole00/mole00270.htm

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any help atall is very much appreciated!!!!!!!!!!!!!!!!

[skyhook]

er..no one said anything ? I'll give it a go, but I've not done it before. What is described could be preparing the culture medium meant for bacteria or probably mould and fungi. Plants tissue culture use different ingredients.

I think beef bouillon is beef stock. It is in dry form.

The usual way of sterilising it, is to autoclave it. But autoclaves are expensive( to me), and over at my country, only labs and doctors have it. Some heat resistant bacteria spores will be present if you just heat it to boiling point. Autoclave goes up to 121for 25 min and 132degC for 5 min, which effectively sterilize it. otherwise there is a method called tindallization which is less effective. or pressure cooking it.

and when you innoculate your culture, in labs they do it at a laminar flow cabinet. If you are DIYing something , you may need at least a box that is sterile inside. If you didn't use a sterile box, various types of bacteria or mould in the air gets onto the medium the moment you open the lid of the medium container, and the medium will be contaminated. but it depends on what is the purpose of doing it. Simple experiments will not need that much preparations.

 

bacterias can be quite dangerous. or I'm just paranoid.

Edited March 21, 2010 by skyhook
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[CharonY]

There is also beef boullion available that is made for bacterial cultivation. Generic stock soup may or may not work with certain bacteria as the composition will vary a lot. My guess however, is that you will most likely grow mold on it. Also if you manage to randomly grow bacteria, be aware that you may have large amounts pathogens in it.

Technically it is not that different from having spoiled food around, though. And also many microorganisms hydrolyze gelatin, that is why normally agar (which less bacteria can utilize) is normally used instead.

[John Cuthber]

Since the site can't tell the difference between bullion and bouillon, how far do you trust it?

 

there's not a lot of difference between a pressure cooker and an autoclave.

[duckduckgoose]

thanks for all your help so far!!

by beef stock do you mean the stuff u buy as powder? or have to boil the beef bones to make broth? and im only 14 so im just trying to get any advice i can so i can just start off with simple things, as i am maybe thinking about a career in chemistry or biology, lab work. thanks for your help guys, keep it coming!!

 

ryan