Dear All, 

I have been trying to generate retrovirus using 293T and Lipofectamine 2000. But, so far, I don't get detectable virus. I am using pBABE retroviral vector and pCLAmpho expressing vector. Usually, I do the generation on 6-well plate and 2ug retroviral vector, 2ug expressing vector and 10ul lipofectamine 2000 for each well. 

Am I missing something? 

Thanks!