Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Cationic polymers bind albumin to produce turbidity that can be used to quantify the polymer concentration. This study examines the use of turbidometry to measure free polycation in mixtures with DNA to deduce the level of polyelectrolyte binding. However, in mixtures of poly(L-lysine) (pLL) and DNA, polyelectrolyte complexes make a significant contribution to the turbidity observed, depending on the N:P ratio. Mixtures were centrifuged to remove complexes to permit turbidometric measurement of free pLL in the supernatant. Complexes formed at N:P ratios greater than 0.8 showed decreased sedimentation, probably due to increased surface charge interactions with the solvent, or with free polycation in solution. The profile of turbidity produced by sequential addition of albumin is modified when DNA is present in pLL samples, showing increased turbidity at low albumin concentrations. This is thought to result from albumin interactions with pLL/DNA complexes, perhaps inducing macroaggregation and consequent turbidity. Complexes formed at N:P ratios of 2.0 showed the least turbidity with albumin, suggesting the relative stability of pLL complexed with DNA under these conditions.

Original publication

DOI

10.1016/S0927-7765(99)00076-4

Type

Journal article

Journal

Colloids and Surfaces B: Biointerfaces

Publication Date

01/11/1999

Volume

16

Pages

253 - 260