Stock buffer(30% Glycerol)

Dear all,
I am a newbie to C. elegans. when I make the stock of C. elegans according the protocol of wormbook. I find the S buffer + 30% Glycerol has the similar(but not too much) color with LB after sterile by autoclaving. I prepared S buffer first, then added the glycerol (30% volume of S buffer), stirred and autocalved for 30 min under 121 C. I tried several times, the resulting buffer always turn out the LB-like color. Is it normal? or should I sterilize the S buffer and Glycerol separately then mix?
Any input is highly appreciated.


Make up the s buffer + 30% glycerol in one go.

Weigh out the glycerol first, then the other components except for the MgSO4 in a suitable volume. Then autoclave (just once!). Once cooled to 50 degrees or so, add the Mg, so avoiding it precipitating out.

The solution should not look like LB, perhaps too many rounds of autoclaving are responsible, although I doubt you would necessarily see a colour change?

Anyway, try it and see…I hope that helps…


Thank you. I’ll try it for adding MgSO4 separately.