TABLE 3.

Changes in γ at the air-water interface for different osmolyte solutions

Solution	Δγair/water, mN/m	σair/water, mN/m	Δγlipid/water, mN/m
Betaine 0.5 osm/kg	0.17	0.09	0.34
Betaine 1.0 osm/kg	0.42	0.15	0.59
Betaine 2.0 osm/kg	0.80	0.165	1.01
Sucrose 0.5 osm/kg	0.58	0.13	0.71
Sucrose 1.0 osm/kg	1.34	0.06	1.27
Sucrose 2.0 osm/kg*	2.78	0.18	2.12
Choline 0.5 osm/kg	−0.03	0.13	0.15
Choline 1.0 osm/kg	0.27	0.2	0.27
Choline 2.0 osm/kg	0.64	0.1	0.63

σ_air/water indicates the standard deviations for the measurements of γ. Δγ_lipid/water is the calculated lipid-water interfacial tension. The large difference between Δγ_air/water and Δγ_lipid/water of sucrose at 2.0 osm/kg is not unexpected as for small area changes the γ can be roughly approximated to be independent of area, though in reality it will depend on the area per molecule, becoming smaller as area per molecule decreases. See text for details.

^*Not used in minimization due to large error in GP.