I have repeated three times this cloning and every time I get numerous
colonies none of which contains any insert. Actually I am trying to
clone a EcoRI cut insert into a vector that is almost 9kb. I check my
clones by colony pcr from the overnight grown single colonies from the
This time I set up a control while performing transformation.
-vector EcoRI cut and purified, I got three colonies
-vector EcoRI cut, column purified and CIP treated and column purified,
I got 7 colonies
-vector EcoRI cut, column purified and CIP treated and column purified
plus insert EcoRI and purified in the ratio of 1:4 and 1: 6. I got
more than 100 colonies.
Can anyone explain what went wrong? None of the colonies contained the
insert when I checked them using primers specific for the insert.
However, control pcr worked. Control contained the insert, EcoRI