Flip-the-Tip

Abstract

A conventional borosilicate glass patch pipette is glued into a plastic jacket, forming the entity of a FlipTip. One or two three-channel modules of recording tip sockets are mounted on a liquid handler platform to take up FlipTips. The tip sockets are connected to preamplifiers (HEKA) and to a suction system. The inner chamber of the tip sockets is filled with intracellular solution (IS), and FlipTips are prefilled with extracellular solution (ES) immediately before use. The FlipTips are then inserted into the recording tip sockets, and suspended cells are taken out of a cell hotel and dispensed into the open back of the FlipTips. Simply by gravity, the cells move down toward the end of the pipette. Continuous gentle suction draws a single cell into the very end of the tip, forming a classical GigaSeal of 1-5GOmega. Stronger suction pulses are then applied to establish the open whole-cell configuration. Under voltage-clamp conditions, the response of an ion channel is measured simultaneously in three to six recording sockets. Alternatively, the perforated patch method is used with Amphoterecine B as the pore-forming agent. Compound delivery is accomplished with a fused silica quartz pipette through the open back of the FlipTip directly onto the cell. All these tasks are performed automatically and completely unattended by the Flyscreen 8500 automated patch-clamp robot. A data throughput of several hundred data points per day can be accomplished with the system.

A Kinetic Map of the Homomeric Voltage-Gated Potassium Channel (Kv) Family

“…Previous studies have found no significant differences in channel kinetics between manual and automated patch clamp system (Li et al, 2017). In addition, we did not find any difference in Kv2.1 kinetics when comparing with data obtained with another automated patch clamp robot (Fejtl et al, 2007) that worked with physiological ICS, ECS, and without the need of SES solution (data not shown). Despite these limitations, the solutions used in this study still contain physiological levels of sodium and potassium concentration to better reflect in vivo ion composition, and not bi-ionic high potassium (K + ) solution as used in many previous studies on potassium channels.…”

CHAPTER 4. Venoms-Based Drug Discovery: Bioassays, Electrophysiology, High-Throughput Screens and Target Identification

“…121,[125][126][127] The Flyscreen 8500 (FlyIon) uses 'ip-the-tip' technology, an adaption of traditional electrophysiology in which suction pulses applied to a cell inside a glass pipette result in true whole-cell conguration, gigaohm seals and resultant high-quality electrophysiology data. 105,128 This platform is fully automated and requires comparatively low volumes of compound. However, with only six electrodes, throughput is low, 105 making the FlyScreen particularly suited to pharmacological characterisation of venom components in limited supply.…”