In article <5csrb7$1uso at power5.rz.uni-hohenheim.de>, intelman at uni-hohenheim.de says... > > >The guys in my laboratory prepare it by solving >5 mg rifampicine in 500 µl of methanol. End concentration is 10 µg per ml. 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.