Poly-l-lysine, poly-α, γ-diaminobutyric acid and basic proteins cause efflux of betacyanin from beet root tissues to varying degrees. Membrane activities fall in the order: polylysine > poly-α, γ-diaminobutyric acid > polyarginine (protamine), suggesting the importance of steric factors in side-chain to backbone relations. It was also observed that homopolymer activity > heteropolymer activity, using ribonuclease and lysozyme as examples of the latter. Among polylysines, there appears to be an optimal chain length at a molecular weight equal to 50,000. Lowered activity of larger polymers is interpreted in terms of a diffusion barrier, the cell wall.