Josiah Passmore

@jpassmore.bsky.social

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Making cells run in circles, and gels with squares in them. Automated optogenetics, Smart microsopy, Expansion microscopy, GelMap. Postdoc @ Utrecht University | visualise.bio.

Fluorescence microscopy of an MRC5 cell highlighting the microtubule and actin cytoskeleton. Stained with: 🔵 DAPI – Nucleus (blue) 🟠 Tyrosinated tubulin – Dynamic microtubules (orange) 🔷 Acetylated tubulin – Stable microtubules (cyan) ⚪ Phalloidin – Actin filaments (grey)
A HT1080 cell guided in a circle path in a crowd of unguided HT1080 cells.
Three cells guided to different overlapping circle paths by automatically updating the area of illumination with outcome-driven microscopy.
Controlling the same cell three times to various setpoints reaches very similar nuclear intensities.
Results of controlling a cell to specific intensities - a cell is brought to various setpoints of cytosolic intensity. Comparison of a standard PID controller and a gain-scheduled PID show that gain scheduling minimises error at all timepoints.
Outcome-driven strategy for controlling nucleocytoplasmic transport using a PID controller. Acquisition-Processing-Control-Intervention.
A video of three cells moving to three different paths, controlled by automatically updating the area of illumination. When a collision is detected, the cells temporarily reverse direction.
Video of a cell moving in a circle, kept to a circle path by automatically updating the area of illumination. If the irradiance is changed, the cell speeds up or slows down accordingly.
Video of a cell moving in a circle, kept to a circle path by automatically updating the area of illumination.
Code schematic for outcome-driven microscopy platform, with modules for image analysis, controller type and microscope bridge - coordinated by an outcome-driven strategy. A python interface interacts with the optogenetic stimulus and acquisition hardware.
Schematic of closed-loop feedback: 1) Image acquisition 2) Image processing 3) Control algorithm 4) Stimulus adjustment.
HT1080 cells with various morphologies. DAPI (blue) Phalloidin (grey) GM130 (green).