A method of immobilizing a cell on a support, the method comprising a) providing a compound or salt thereof comprising two hydrophobic domains attached to a hydrophilic domain, wherein the two hydrophobic domains are covalently bound to said hydrophilic domain, and wherein the one or more hydrophobic domains each comprise cholesterol, and wherein the hydrophilic domain comprises a polyethylene glycol moiety, and wherein the compound comprises a biotin group; b) contacting a cell with the compound under conditions allowing the interaction of the compound with the membrane of the cell, thereby immobilizing the biotin group on the surface of the cell; and c) contacting the biotin group immobilized on the cell with a support capable of binding the biotin group, thereby immobilizing the cell on the support, and wherein the hydrophilic domain of the compound or salt thereof of step a) comprises a compound of Formula: X1-[A1- n] k1 -Z-[A2- n] k2 -X2, wherein Z is linear polyethylene glycol moiety containing 1 to 50, preferably 4-30 -O-CH 2 -CH 2 - moieties, wherein the polyethylene glycol moiety optionally comprises 1 or more spacer moieties SP connecting two -O-CH 2 -CH 2 -moieties, and wherein the linear PEG moiety optionally comprises a linker moiety L3 at one or both ends, each L1 is a linker moiety selected independently from each other from the group consisting of a phosphate, amide, carbamate and ester group, each n is either 0 or 1, selected independently from each other, A1 and A2 are bifunctional or trifunctional moieties selected independently from each other, with the proviso that at least one A1 or A2 is trifunctional, wherein a bifunctional moiety is selected from the group consisting of a phosphate group, carbamate group, amide group, a moiety comprising a nucleobase, preferably dT, and a linear alkyl group having 1 to 10 C atoms, and which alkyl chain contains functional groups at the terminal C-atoms, and wherein a trifunctional moiety is a moiety containing three functional groups prior to the synthesis of said compound and which is selected from a trifunctional moiety having 1 to 10 C atoms, and comprising at least one -OH, -SH and/or at least one -NH 2 group, preferably selected from lysine, serine, serinol, -O-CH 2 -CH((CH 2) 4 -NH 2)-CH 2 -, a glycerol, and a 1,3 diaminoglycerol moiety, k1 and k2 are integers between 0 and 10, selected independently from each other, with the proviso that at least one of k1 and k2 is not 0, X1 and X2 are independently selected from hydrogen or a protecting group, L3 is independently selected from a linear alkyl or alkenyl chain with 1 to 10 C atoms, which is optionally (i) interrupted by 1 to 3 N, O or S atoms, and/or (ii) substituted by 1 to 4 hydroxyl, carbonyl, amino or thiol groups, and wherein the one or more hydrophobic domains are covalently bound to said hydrophilic domain via the trifunctional domain(s). a) providing a compound or salt thereof comprising two hydrophobic domains attached to a hydrophilic domain, wherein the two hydrophobic domains are covalently bound to said hydrophilic domain, and wherein the one or more hydrophobic domains each comprise cholesterol, and wherein the hydrophilic domain comprises a polyethylene glycol moiety, and wherein the compound comprises a biotin group; b) contacting a cell with the compound under conditions allowing the interaction of the compound with the membrane of the cell, thereby immobilizing the biotin group on the surface of the cell; and c) contacting the biotin group immobilized on the cell with a support capable of binding the biotin group, thereby immobilizing the cell on the support, Z is linear polyethylene glycol moiety containing 1 to 50, preferably 4-30 -O-CH 2 -CH 2 - moieties, wherein the polyethylene glycol moiety optionally comprises 1 or more spacer moieties SP connecting two -O-CH 2 -CH 2 -moieties, and wherein the linear PEG moiety optionally comprises a linker moiety L3 at one or both ends, each L1 is a linker moiety selected independently from each other from the group consisting of a phosphate, amide, carbamate and ester group, each n is either 0 or 1, selected independently from each other, A1 and A2 are bifunctional or trifunctional moieties selected independently from each other, with the proviso that at least one A1 or A2 is trifunctional, wherein a bifunctional moiety is selected from the group consisting of a phosphate group, carbamate group, amide group, a moiety comprising a nucleobase, preferably dT, and a linear alkyl group having 1 to 10 C atoms, and which alkyl chain contains functional groups at the terminal C-atoms, and wherein a trifunctional moiety is a moiety containing three functional groups prior to the synthesis of said compound and which is selected from a trifunctional moiety having 1 to 10 C atoms, and comprising at least one -OH, -SH and/or at least one -NH 2 group, preferably selected from lysine, serine, serinol, -O-CH 2 -CH((CH 2) 4 -NH 2)-CH 2 -, a glycerol, and a 1,3 diaminoglycerol moiety, k1 and k2 are integers between 0 and 10, selected independently from each other, with the proviso that at least one of k1 and k2 is not 0, X1 and X2 are independently selected from hydrogen or a protecting group, L3 is independently selected from a linear alkyl or alkenyl chain with 1 to 10 C atoms, which is optionally (i) interrupted by 1 to 3 N, O or S atoms, and/or (ii) substituted by 1 to 4 hydroxyl, carbonyl, amino or thiol groups, and wherein the one or more hydrophobic domains are covalently bound to said hydrophilic domain via the trifunctional domain(s).