(how quickly the synthesis of first protein molecule is complete) 12h or less or more (not necessary at a detected level but even if it only minimally expressed)
"not necessary detected but even if it only expressed"
How do you think one would determine the expression without detection?
Adenovirus is very infectious and rapidly gets into most cells - 5 min is enough, but it's also a matter of mass action. If you hit cells with ~1000 AV/cells, some will get in a very minutes. Of course, assumption is that the quality of vector is excellent.
The next step, from practical standpoint, is DNA gaining entry into the nucleus - takes a little longer - several hours. Then depending on the strength of promoter and enhancers present in the gene construct, transcription could be very efficient or very slow. Similarly, depending on the design, rate of translation can vary by more than an order of magnitude.
in order to answer your question, how quickly the synthesis of first protein molecule is complete (assuming you are not thinking about RNA), you have to put far more thought into what is it that you are looking for... there are no universal truths here.
thank you all for your answer, I asked this general question because I didn't find an efficient antibody to detect the protein with a good visible intensity in WB after trying many commercial and in-house antibodies, so I thought that the time point is what affecting my results, I can detect a good rise of its mRNA and its effects in less than 24h but not the protein band.