Help. Lentivirus. Good titer but no transduction - (Feb/10/2012 )

Hello, I am working with lentivirus particles, when I do the transfection of the viral plasmid in Lenti-x cells I can see the fluorescence of the GFP whithout problems. I have made the titration by ELISA of the protein p24 and the titer es 1.2*10E10 with a p24 lentivirus titer of Clontech. My problem is when I transduct neurons from primary culture o cell lines like lenti-x, hek293, or NSC34( motoneuron cell line) I can´t se the expression of the GFP.

Anybody can help me????????? Please I do not what can I do.

Have you tried different concentrations of the virus?
Have a positive control for the transduction.

How long have you incubated cells with virus?

Yes, I tried diferents dilutios 10 to -1 -2 -3,-4,-5.
I have incubated 24 h and 48 h with the virus and I have tried to be the expression 1,2,3,4,5 days after the infections.

Thank you very much!

My suggestion would be to try the highest titer you can try, 1*10E10 . If you dont see anything here, then its a problem. Also try a positive control virus, if you have access to one.

Wait for up to 1 week with neuronal cultures. A lot depends on the promoter too. It can take longer if the promoter is a very weak one.