Microfluidic array platform for simultaneous lipid bilayer membrane formation

Screening ion-channel ligand interactions with passive pumping in a microfluidic bilayer lipid membrane chip

“…The bilayer chips are simple to manufacture from dry film resist and the passive pumping method eliminates the need for unwieldy syringe pumps and tubes with associated material wastage. 7,8,19 The perfusion system was demonstrated using three model systems: (1) a-HL insertion on the cis side, with b-CD blocker introduced to and flushed out of the trans flow channel, (2) a-HL transient blocking with different molecular weight PEGs via the flow channel, and (3) KcsA-E71A proteoliposome fusion from the cis compartment, and concentration-dependent TEA þ blocking of the bilayer-incorporated KcsA mutant from the flow channel. Compared with traditional bilayer electrophysiology systems, 28,29 which use large-volume cups and an aperture in a Teflon septum, both the bilayer and the shunt capacitance are considerably reduced, resulting in higher quality electrical recordings (see supplementary material Fig.…”

“…Parallel recording techniques from multiple bilayers are being pursued 7,8 and improvements in bilayer stability and the ease of bilayer formation have been demonstrated, for example, through the use of smaller apertures over micro-cavities and nanopores. [9][10][11][12] Although small apertures are preferable for stable bilayers, the smaller integrated Ag/AgCl electrode can restrict recording time to a few hours.…”

“…Such conditions are often required for ion channel measurements, for example, electrophysiological characterization of the potassium channel KcsA requires an acidic pH on one side of the bilayer. 16,17 In a traditional macro-scale bilayer membrane system, 7,8,17,18 the bilayer is produced across an aperture in a thin hydrophobic material, typically Teflon, separating two cups, providing access to both sides of the bilayer. However, the bilayers are mechanically fragile, and solution exchange is problematic.…”

“…This issue has been addressed by making smaller systems, incorporating micro-channels for solution exchange. 8,17,[19][20][21][22] For example, Stimberg et al described a flow channel, where the microfluidic channel and bilayer aperture are made separately and glued together and fluid is flown across the bilayer using a syringe pump. 19 Shao et al demonstrated a bilayer microfluidic platform that enabled rapid perfusion of liquid (>2.5 ll/min), with 100 ll samples, 21 and Le Pioufle et al demonstrated an array of wells, each with multiple small bilayers with fluidic access to both sides, where electrical recordings were performed by moving an Ag/AgCl electrode from well to well.…”

Scalable micro-cavity bilayer lipid membrane arrays for parallel ion channel recording

“…Recently it was demonstrated that the stability of artificial bilayer membranes can be significantly increased by using shaped apertures fabricated in negative resists such as SU8 [7], or complex (incline/rotation) exposure technique [8]. In order to increase throughput, bilayer arrays have been developed, for example using stereo-lithography to define chambers around a thin film of a hydrophobic polymer that includes an aperture for bilayer formation [9,10]. Both ease of bilayer formation and stability has been improved through the use of small cavities in the range 6-50 m diameter [11][12][13].…”