i use 5ug/ml for the final stimulation.& [" m; v0 }/ O& w; Q
stock is 5mg/ul in water and then passing though 22um membrane.8 |1 r5 F1 F, V
keep the stock solution at 4 degree, and i think 3 month should be no problem.+ v: U/ v+ N& ^0 d& V' k$ l* A
keep the powder also at 4 degree.