[BillJames]

I know it shorts for 50% germination half-inhibition for one particular concentration. But... what does that mean?

[sjb]

I know it shorts for 50% germination half-inhibition for one particular concentration. But... what does that mean?

Well, thank goodness you've given some context, else we could have been here all night trying to work out which GC50 you mean!

Basically, the concentration of something, at which 50% of samples are inhibited from growing, compared with untreated standard. (I've never really worked out in these things if that means growing at all, or above a certain rate or ratio)

[BillJames]

Ah, I didn't know it was that simple :p Thanks