Lil math question for you guys...very curious about answers - (Sep/05/2008 )

If I have 10µg of an oligo and 10µg of the complementary oligo and I anneal them in 40µl endvolume,

what is my endconcentration of double stranded oligo?

PhD in the lab says 0.5µgµl

Boss says 0.25 µg/µl

They both state they are sure of what they are saying and im trapped. Logically I would say that if you have two oligos and you anneal them, you get half as many molecules but they weigh 10+10 and a concentration is weight/volume so I agree with the PhD. Then again the boss is the boss she couldnt get something like this wrong right?

the concentration is 0.5ug / ul

But PCR reactions don't use that unit. It is always Molar concentration. Oligos can vary from 6bp to 100bp.

0.5ug/ul

If you put 10 grams of something, A, on a scale and then 10 grams of something else, B, on the scale and the two ( A+B ) happen to bind together, you are still going to have 20 grams of stuff on the scale. It's not like the scale is suddenly go down to 10 grams. Same idea with ug which means you have 0.5ug/ul! I'm sorry to tell you that your boss is (gasp) mistaken.

0.5ug/ul but it doesnt useful!! you always put pF and PR.. I think your boss is wrong. they make mistakes also.

the conc. is 0.5ug/ul.

i think your boss got confused between uM and ug.

Even PI's are human and make mistake, forgive the poor soul.