Polarized cells induced by polyunsaturated FFAs exhibit increased surface affinity. (A) Polarized cells exhibit preferred surface binding at Lo phase of the membrane. M109 cells exposed to 50 μM linoleic acids for 4 days were first detached from culture dishes, then added back to a glass surface, stained with phase-probing dyes, and imaged. Lo phase: green, Ld phase: red, yellow: overlaid of green and red signals. Scale bars: 25 μm. Z = 0 um indicate glass surface cell membrane interface. (B) Surface protein density at Lo phase of polarized cells is higher than average surface protein density of non-polarized cells. M109 cells exposed to 50 μM linoleic acids for 4 days were stained with FITC-conjugated antibodies to vascular cell adhesion molecules, VCAM-1. Random fluorescent unit (RFU), which represents the concentration of VCAM-1, is plotted against cell positions indicated by blue and red lines, which mark a non-polarized and a polarized cell, respectively. 3-D stacked image of 15 frames at 1 μm step size along vertical axis. (C) Polarized cells exhibit increased surface affinity. M109 cells untreated (blue) or treated with 50 μM linoleic acids for 4 days were first detached from the culture dishes, then added back to a glass surface for 45 minutes. Unattached cells were removed with gentle washing. Attached cells were lysed and assayed with CyQuant GR dye for nucleic acids. Fluorescent signals (RFU) are linearly correlated with cell number and indicate cell surface affinity.