Can medium containing starch be autoclaved? - (Nov/21/2012 )

You have to take into account the solubility of the extra solutions you have to make.

e.g. To make 100 mL, if the final concentration of NaHCO3 is 0.4 g/100mL. Make 0.4 g in 10mL. I'm pretty sure you won't have solubility problems with bicarbonate but you have to check it for the starch.
Off course you have to subtract the volume of each separated solution to the main solution (the one with all the other things you don't do separately). In the example the recipe says to bring that solution to 900 mL before

Hmmm, okay. How do I determine how much of the 0.4g in 10ml, I need to add to my final media?

if you need 0.4 g in your final volume, all

So, when I make plates with this recipe, I'll prepare everything, except the NaHCO3, Starch, and L-Cysteine, autoclave. Then, while the media is cooling, I will aseptically, add those three components, which have been filter-sterilized/autoclaved seperately?

Aseptically under N2/CO2 atmosphere, yes

I'm using the following recipe, does this math/reasoning sound right?

For my enrichment, I currently have 40 mL in a serum bottle with all the components, except for my carbohydrate, NaHCO3, and CyS.

Per every 100 mL, the recipe says, I need 0.4g of NaHCO3 & 0.6g Carbohydrate

I take 0.4g NaHCO3 in 10 mL of DI Water (Sparge & Autoclave)
0.6g Carbohydrate in 10 mL of DI Water (Sparge & Autoclave)

Since, I only have 40 mL in my serium bottle, I would need to add 0.16 mL of NaHCO3, and 0.24 mL of Carbohydrate in my serium bottle....correct?

for 100ml you need 0,4 grams,

so for 40 ml you need: 0,16 grams (2.5 times less)


If you hav 10ml DI water with 0,4 grams and you only need 0,16 grams, then how much DI water do you need to take?
10ml = 0,4 grams
xml = 0,16 grams.

X= ?

if you cant figure it out, make easier for yourself.

10 ml = 0,4 grams ==> 0,1 grams is 10/4ml or 2,5 ml
so for 0,16 grams, you mulitply 2,5 with 1,6, wich makes: 4ml.

I dont understand why you are making it yourself so difficult,

why do you make that 10ml solution?
WHy not just add the amount you need to the serum boittle at once?

Hi, thanks!

I have to set up multiple enrichments with multiple carbohydate sources, so I prepared a large amount of the media except for those three components and divided it into multiple serum bottles.

So, I think I should create a stock solution of my carbohydrate in case I need to prepare this enrichment again.

The original recipe calls for 0.6g of carbohydate for every 100 ml of enrichment prepared. I can prepare a stock of 0.3g in 50 mL so that my stock solution is 0.6%. If I prepare only 40 mL of enrichment, then I will take 0.24 mL of my 0.6% carbohydrate stock solution correct?

In retrospect, I'm thinking now that I should have not made my enrichment the even 40, but accounted for adding the carbohydrate, reducing agent, and Na2CO3......

SunsetSatine on Thu Dec 6 16:13:40 2012 said: