Hi,
Don't worry, it usually takes me ages to work things like that out!
Basically, 1mM = 1mmol per litre or 0.001mmol per ml or 0.000001mmol per ul
If you then multiply by the correct factor to get to pmol (in this case 1000(to get to umol) x 1000(to get to nmol) x 1000 (to get to pmol) = 100 000 000 total)
Sooooo, 1mM = 1000pmol/ul
i think that's right!! Does it make sense???