should 3' and 5 ends of synthesised cdna be subjected to amplifictaion before insertion into vector?

Cloning vectors are double stranded (ds) so you would need to generate ds insert, usually via PCR, but you only need to do "first strand" cDNA synthesis using either a sequence specific reverse primer that anneals downstream of the translation stop signal or an oligo-dT primer that anneals to the polyA tail.

PM