Osmotic pressure contribution of albumin to colloidal interactions.
Two surfaces that come in close contact in a solution with macromolecules present experience an attractive force caused by the osmotic pressure. We present a measurement of this effect by using a micrometer-sized sphere bound to a flat plate through a single molecular attachment in an albumin-containing solution. We obtain the osmotic part of the interaction potential with a resolution of <1 nm and a fraction of kTroom. This attractive interaction is seen to have a range comparable to the size of the albumin molecule. The results are broadly in agreement with a geometric model first proposed by Asakura and Oosawa.
Singh-Zocchi
M
M
Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen O, Denmark.
Andreasen
A
A
Zocchi
G
G
D000418:Albumins / Q000737:chemistry*; D000818:Animals; D003102:Colloids; D009997:Osmotic Pressure
D000418:Albumins; D003102:Colloids