I want to use it for one of my media composition.
since the solubility of biotin in very less, reported to be 0.02%, I cannot use it for pilot scale media composition as filter sterilization would be unpractical with that enormous volume.
The requirement in my medium is 0.2g/liter
You could have success with first preparing a diluent that is 10% DMSO v/v:
e.g. 10 mL DMSO + 90 mL water. Then add 0.4 g D-biotin powder to that.
This would give you a solution that is 0.4 g/100 mL, which = 4 g/1000mL (or 4 g/L) D-biotin stock.
Then, to attain 0.2 g/Liter in your medium, you would merely add 50 mL of the above solution + 950 mL of medium. Or 5 mL + 95 mL of medium.
This would end up giving you 0.2 g D-biotin/Liter medium. It would also end up giving you 0.5% DMSO in your final medium as well, so you should be sure that 0.5% DMSO in your final medium does not bring about undesirable effects in whatever system you are dealing with.
Or, even more simply: add 0.2 g of D-biotin to 5 mL DMSO to create a 40 mg/mL solution. Then, take that entire 5 mL and add it to 995 mL medium.
This will give you 0.2 g/L D-biotin, and 0.5% DMSO final concentrations.
hey jack. thank you. need to check if my media can be indirectly supplemented with DMSO.
could you comment on the stability and pH of the above biotin solution. thank you.
That you'll have to find out empirically~ And you probably don't have to worry too much about a pH change in your media with a 1:200 dilution of the 5 mL stock D-biotin in DMSO by adding 5 mL to 995 mL media; the buffering capacity of your medium will certainly be able to withstand this...
The issue with D-biotin is that it is a carboxylic acid and as such it decreases pH of aqueous solutions. Under acidic conditions D-biotin is however less soluble. My advice therefore is to use DMSO or an alkaline buffer (pH ~7.5) instead of water to prepare concentrated D-biotin solution.
As per the solubility is concerned biotin is about 50 times more soluble in DMSO compared to alcohol. You can prefer DMSO if it is compatible with your experimentation.
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