mysterious puzzle in result of confirmatin the protein expression after 3 years - (Dec/17/2008 )

Hi All,
i did confirmation of my friend experiment that he did in 3 years ago because i want to check an experiment system completely , i surprised by my experiment doesn't succeed in my protein expression, , And i am completely sure i used ( same plasimd & strain ) and i repeated doing that with no vail.I'm sure my friend get expression because he showed me his pictured gel regarding good expression of target protein of Both pKK223-3 and PQE-30 vectors in DH10B and Top10 respectively .
please any suggestions to solve this trouble !!!!
Thank again

-dawood-

QUOTE (dawood @ Dec 18 2008, 02:56 PM)

Are you using his clones or using your newly transformed one? Try using his clone. which did have result before. Streak that clone on plate and pick several colonies to test. Just induce and run bacterial lysate first (uninduced v.s induced) to see if you have proteins there. Keep a bit of culture for miniprep and PCR, sequencing if necessary to see if you lost the construct. Follow his protocol EXACTLY. Would be best if you can ask him to do a parallel exp.

-Almasy-

hmm.... is it possible to get your friend to come into the lab and show you how he expressed the protein?

-perneseblue-