What Are the Detailed Operating Steps for a Cell Adhesion Force Measurement Instrument?

　　Cell Adhesion Force Measurement Instrumentis a specialized instrument for precisely measuring interaction forces between cells and a substrate, with important applications in cell biology, biomedical engineering and related fields. By accurately measuring these interactions, it helps researchers understand cell behavior and disease mechanisms and develop new treatments. For example, the CellHesion 200 system from Germany’s JPK measures cell–cell and cell–substrate interactions, quantitatively measures cell elasticity and responses to external mechanical pressure, and provides single-cell quantitative results with single-molecule precision. Its innovative method supports cell-interaction research with high-quality data, and its software automatically determines key parameters related to cell adhesion force.

　　Cell Adhesion Force Measurement Instrumentoperating steps:

　　I. Experimental Preparation

　　Select the Matrix Protein

　　Select an appropriate matrix protein, such as collagen, fibronectin or laminin, for the research objective. Prepare it in PBS at a suitable concentration, such as 2-10μg/mL, and coat the bottom of an assay plate such as a 96-well plate evenly. Incubate overnight at 4°C or for 1-2 hours at 37°C to immobilize the protein.

　　Block Nonspecific Binding Sites

　　Block the assay plate at room temperature with 1%BSA (bovine serum albumin) or 10% fetal bovine serum for 30 minutes to 1 hour to reduce nonspecific cell adhesion.

　　Cell Preparation

　　Select cells in logarithmic growth, digest them with trypsin, collect them by centrifugation and resuspend them in serum-free medium. Adjust the cell concentration to 5×10⁴-5×10⁵/mL according to cell type.

　　II. Instrument Setup

　　Calibrate the Sensor

　　Following the instrument manual, calibrate the force sensor with a reference sample such as cells or material with known adhesion force, ensuring measurement accuracy with typical resolution of 0.1nN.

　　Set Parameters

　　Contact time: set the cell–matrix contact time according to the experiment, for example 5, 10, 15, 20 or 25 minutes.

　　Retraction speed: set the probe-retraction speed, such as 1μm/s, to ensure stable dynamic measurement.

　　Environmental control: if the instrument includes an environmental-control module, set parameters such as temperature at 37°C and CO₂ at 5% to simulate physiological conditions.

　　III. Cell Handling and Seeding

　　Seed the Cells

　　Add the cell suspension to the matrix-protein-precoated assay plate at 5000-1×10⁵ cells per well, adjusted for plate size, and use 3-5 replicate wells to reduce error.

　　Incubation

　　Incubate the assay plate in a constant-temperature incubator at 37°C and 5% CO₂ for the specified period to allow complete cell attachment.

　　IV. Measurement

　　Remove Unattached Cells

　　After incubation, gently wash the assay plate 2-3 times with prewarmed PBS to remove unattached cells.

　　Fix the Cells (Optional)

　　For long-term storage or subsequent staining, fix the cells in 4% paraformaldehyde for 15-20 minutes and then wash with PBS.

　　Start Measurement

　　Mechanical method: lower the hollow probe until it contacts the cell surface. Stop when the force-measurement output reaches the set threshold, such as 50nN. After the specified contact time, retract the probe at the set speed, such as 1μm/s, through a distance of 60μm and record the force–displacement curve.

　　Fluorescence method: when fluorescent labeling is used, measure intensity with a fluorescence microplate reader—for example, calcein labeling at an excitation wavelength of 488nm and emission wavelength of 520nm. Fluorescence intensity is proportional to the number of adherent cells.

　　Microfluidics: apply shear force in a microchannel, such as 0.5-5 dyn/cm², to simulate physiological flow and monitor cell-adhesion dynamics in real time.

　　V. Data Recording and Analysis

　　Extract Key Parameters

　　Extract maximum adhesion force, adhesion time, adhesion area and other parameters from the force–displacement curve, or calculate adhesion rate from fluorescence intensity using: adhesion rate = (experimental-group OD / maximum-adhesion-group OD) × 100%.

　　Statistical Analysis

　　Use software such as GraphPad Prism for ANOVA, calculate the standard deviation and coefficient of variation, and verify statistical significance at p<0.05.

　　Visualization

　　Plot adhesion-force-versus-time curves, adhesion-rate bar charts and other visualizations, and combine them with microscopy images such as crystal-violet or Giemsa staining to present the results clearly.

　　VI. Post-Experiment Cleanup

　　Clean the Instrument

　　Clean probes, culture dishes and other components with deionized water or a dedicated cleaner so residue does not affect the next experiment.

　　Shut Down the Instrument

　　Shut down the environmental-control module, optical module and software system in sequence, then switch off the power.

　　Data Backup

　　Save raw data to a local drive or cloud storage and create an experimental record for traceability.