Question: how to do a gbs swab?
Answer: Vagina, (front passage) Anus, ... 
Insert swab 2cm into vagina, (front passage). Do not touch cotton end with fingers. Insert the same swab 1cm.
into anus, (back passage). Remove cap from sterile tube. ... 
cap fits firmly. Make sure swab container is fully labelled with name, u.r. number, date and time of collection.