In article <5csu28$g8f at bignews.shef.ac.uk>, C.Pical at shef.ac.uk says... > > >That looks impossible to me (5 mg in 0.5 ml = 10mg/ml). Usually >rifampicine is dissolved in methanol or DMSO at 50-100 ug/ml. > Seems I (my mind) was lost in somewhere. Of course, should have been 50-100 mg/ml, and the final concentration in ug/ml. Sorry, C.