To study lipid-Gag interactions, we use multiple in vitro approaches including the giant unilamellar vesicle (GUV) binding assay. The image shows an example of a GUV consisting of two different lipid phases (one of which contains a red dye). Gag-YFP (green) is specifically bound to the phase that does not contain the red dye.

(Olety, Veatch, and Ono. 2015)