In this study, cellular membrane fragments from SH-EP1-pCEP4-hα7 and α7 HEK-293 cell lines were used to synthesize cellular membrane affinity chromatography (CMAC) columns containing functional α7 nicotinic acetylcholine receptors, CMAC(α7 nAChR) columns. The synthesis of stable columns required the addition of cholesterol to the 2% cholate solubilization/immobilization (s/i) buffer and to the mobile phase. In addition, when membranes from the SH-EP1 cell line were used, L-α-phosphatidylserine and L-α-phosphatidylethanolamine also had to be added to the s/i buffer. A CMAC(α4β2 nAChR) column was prepared using membrane fragments from a SH-EP1-pCEP4-hα4β2 cell line, and this process required the addition of L-α-phosphatidylserine and L-α-phosphatidylethanolamine to the s/i buffer, but not cholesterol. The s/i buffers from the three columns were compared with the s/i buffer utilized in the preparation of a CMAC(α4β2 nAChR) column prepared using an α4β2 HEK-293 cell line, which required no additions to the 2% cholate s/i buffer. The data demonstrate that both cell type and receptor type affect the protocol required to produce a stable CMAC column and that, at the current time, the development of an optimum immobilization protocol is an empirical process. The results are also consistent with the observation that the α7 nAChR is localized in lipid rafts in both of these cell lines and that the cholate detergent removed cholesterol from these microdomains.Neuronal nicotinic acetylcholine receptors (nAChRs) are ligand gated ion channels that are composed of five transmembrane subunits oriented around a central pore. 1,2 To date, 12 different neuronal subunits have been identified, 9 α subunits (α2-α10) and 3 β subunits (β2-β4). These subunits combine to form a wide variety of homomeric α x subtypes where x = 7, 9, 10 and heteromeric α x β y subtypes where x = 2, 3, 4, 5, 6, and y = 2, 3, 4.The homomeric α7 nAChR is found in the mammalian brain, 3 and these receptors appear to be involved in learning and memory 4 and to play a role in Alzheimer's disease. 5,6 The receptor is also involved in schizophrenia through the mediation of the release of GABA by