Versatile Horizontal Force Probe for Mechanical Tests on Pipette-Held Cells, Particles, and Membrane Capsules

Abstract

We present a multipurpose nanomechanical force probe that combines a sideways-mounted elastic cantilever and an optical-lever detection module with automated micropipette manipulation. It allows us to apply and measure compression, stretching, adhesion, and dissociation forces in the horizontal direction while providing a "side view" of ongoing experiments. The integrated micropipette setup facilitates the easy manipulation and mechanical interrogation of individual cells, functionalized particles, and synthetic membrane capsules. Pipette-held test objects are translated perpendicularly to and from the stationary cantilever, eliminating the need to attach them to a carrier surface and substantially reducing unwanted hydrodynamic coupling effects. Moreover, the test objects can be brought into contact with the cantilever anywhere along its length, which considerably enlarges the range of forces that can be applied with a single cantilever. Advantages of this instrument are demonstrated in example measurements of single-cell compression, membrane-tether extrusion, oligonucleotide stretching, and extraction of individual lipids from surfactant-monolayer surfaces of microbubbles.

Investigation of the strength of micro-objects by NanoScan scanning nanohardness tester

“…Для механической характеризации подобных объектов часто используют нанотвердомеры или атомно-силовые микроскопы [18][19][20][21][22] Fig.1…”

“…обычного кантилевера с иглой на конце приме-няют кантилеверы без острия, и механическое воздействие на частицу оказывают кончиком кантилевера или закрепленным на нем специ-альным микроскопическим шариком [22]. Также используются наноинденторы в виде цилин-дрического штампа с плоским кончиком [18][19][20][21].…”

“…For the mechanical characterisation of these items often use nanohardness testers or atomic force microscopes [18][19][20][21][22], in which for the mechanical impact on a particle the tip of the cantilever or a special microscopic bead attached to it [22] are used. Also used are nanoindenters in the form of a cylindrical die with a flat tip [18][19][20][21].…”

Adhesion Frequency Assay for <em>In Situ</em> Kinetics Analysis of Cross-Junctional Molecular Interactions at the Cell-Cell Interface

“…Although we exemplified the adhesion frequency assay using a micropipette-aspirated RBC as an adhesion sensor, other force techniques can be used, including atomic force microscopy 24 , biomembrane force probe 8,17 , optical tweezers 25 , and the integrated micropipette and cantilever 26 .…”

Structural and Mechanical Mechanisms of Ocular Tissues Probed by AFM

“…One of the most relevant advances was the introduction of the optical lever deflection method, which facilitated the generalized application of the AFM to study biological samples under liquid conditions [108,109]. Recent advances in the biological field include the differential force microscope, which uses an additional reference lever to minimize drift between the tip and the sample for long time measurements [111], and the horizontal force probe to enable lateral force measurements with lateral visualization of the system [112,113]. Other advances include the use of position detectors (strain gauge or capacitive) to monitor the actual position of the piezoelectric elements, to correct for inherent hysteresis and creep effects, and to allow more accurate repositioning of the tip, especially with the long ranges used when dealing with whole cells or parts of tissues.…”