Question on negation.

    I am a recent subscriber to B-Greek, so excuse
my lack of experience when it come to the wording
of my question/questions.
    I am looking for documented proof on the use of 
the 'ou' and 'me' negatives.  I realize that 'ou' is
for the negation of indicatives, while 'me' covers non-
indicatives, but does 'ou' negate the next indicative
in the sentence.
    The reason for my asking is Rom 7:15,19.  All other
negation of indicative verbs with 'ou' is handled differently.
Is there a reason for this one section being different?
    Thank you for your time in reading this message and for
any assistance that you may offer.

                               Grace and Peace to All