[BHP]
(2-3)
A-CBHCt*
£BHP£_eBH
Before any DNA has been added, the total absorbance of
the solution will be due entirely to free BH and, since
BH at this point will be equal to C^, the total absorbance
before any titration, Aq, may be expressed as
A0 = £BHCt (2-4)
Similarly, when all of the compound has been bound, the
final absorbance, A is equal to
A
00
eBHPCt*
(2-5)
and for any point in the titration, where the total absor
bance is Afc,
[BHP] = [(At-Ao)/(Aoo-Ao)]Ct (2-6)
and
[BH] = [l-(At-Ao)/(Aoo-AQ) ]Cfc (2-7)
Since an appreciable amount of the total 7-amino-
quinoline exists in the solution in the neutral form at
pH 5.9, the equations representing the protolytic equilibrium,