5x met/cys media

[Dr Engelbert Buxbaum]

Am 10.05.2007, 16:18 Uhr, schrieb Lisa Imboden <limbode from emory.edu>:

> I can't figure out the best way to make media containinng 5X met/cys.   
> I've read that met and cys are both susceptible to oxidation and  
> therefore need to be made in degassed water.

Dissolve the amino acids at, say, 100 x the required concentration in  
water and sterile-filter. Note that you may need a counter ion (acid or  
base) to get them into solution. The sterile stock solution can then be  
added to the medium, like you do with other additives. Degassing the water  
is easy. Distilled water is, of course, ipse facto also degassed. Water  
purified by ion exchange or reverse osmosis is sonicated a couple of  
minutes or stirred while conected to a vacuum pump.