4th MAY, 2020
Webinar Summary
Possibilities or the sources of contamination in the home made media.
We discussed 3 main parts which could help us in solving out the problems!
1. The components or the ingredients used for making the homemade media
2. Cooking
3. Autoclave
1.When we look at the first part i.e. components or the ingredients used for making the homemade media…
While comparing with the Standard Corn Meal Media
Dextrose and sucrose are a source of sugars,
Maize powder a source of carbohydrates,
Yeast extract a source of proteins, vitamins and minerals and
Agar as a solidifying agent.
Now when we look to the ingredients in our Tomato Rava Homemade Media,
Table sugar is a source of sugar as in cornmeal media
Rava is a source of carbohydrates (73g in 100g rava)
Tomato puree is a source of proteins, vitamins and minerals
Rava here in this media acts as a solidifying or a binding agent as well.
So when we look at the components or the ingredients used…they are just perfect when compared with each other!
We were now clear with the first part!
2. Coming to the second part i.e. COOKING
We are not cooking just for the purpose of cooking for some time or so.
There is a purpose behind cooking.
What if we don’t cook?
was the question raised by @Arunan Sir.
We have in our mind that we require a solid consistency of the media.
Why do we need a solid consistency?
was the next question.
If we get a liquid medium then that won’t support the culturing of flies in a bottle
The flies would get stuck to the media and then they die!
What is this solid consistency, like how is it’s shape?
The media after pouring in the bottle should take the shape of the bottle or the container and should have an even surface!
If not an even surface, then the flies might get stuck somewhere and then they die!
All these factors should be kept in mind!
What is this cooking? Till what time do we cook? What should we achieve by cooking?
We need a homogenised mixture or a medium.
For this we need to cook properly.
What do we mean by cook properly?
We need to cook the ingredients in water till we are sure that all the components have dissolved in the water and are mixed completely.
Here the time take for cooking is not what is concerned rather, the homogenisation of the media is what we are looking for!
This is what is done with the standard cornmeal media too!
If there is excess of water, we can evaporate it by cooking while the ingredients are being mixed in the water.
Should not overcook as added by @ankitcube
Do not cook till the media gets thick or till it gets too thick in its consistency
Otherwise it would be difficult while pouring this media in the bottles.
If this much is taken care of, then we can to very much extent prevent the growth of bacteria or fungi or whatever unwanted growth was seen!
3. The third part i.e. AUTOCLAVE
We all have a pressure cooker at home.
As suggested by @Arunan Sir, we can pressure cook it for once and then our media is ready.
This much can be tried out and we can achieve what we want!