short ssDNA cloning

[Domo]

Hallo,

Could somebody give an advice how could I clone single stranded DNA?

To conform full-lenght mRNA, I am planning to perform RACE with
specific DNA oligo, which binds ~100 nt (50 - 200 nt ok) bp from
5'-end of mRNA.
Then I want to clone this short ssDNA oligo and sequence it.

It is possible to introduce specific sequence to 5'-end of oligo. So I
could capture this end using specific restriction site with dsDNA
vector. Hovewer, the problem remains with random 3'-end. Should I use
random adaptor NNNNN?

I would like to obtain DNA sequence from cap site RNA, since not all
RNAs have polyA.

Any suggestions?

Appreciate your help,

Domo