[Django]-Django admin url filter won't work

I’m answer my own question because it seems the Django community is not so active on these issues.

I’ve found the answer here. The problem was that apparently the query string shouldn’t contain the values of the IN clause enclosed in square-brackets. So, the expression should be: http://localhost:8000/admin/fantoddcc/rnaextracts/?biosamples__biosamplesetid__in=57,52,51,50,49

Your are welcome.