Domain: Natural Science — Cell & Developmental Biology
Target concept: Neutrophils migrate toward a chemotactic attractant micropipette under the microscope.

Video generation prompt: A chemotactic factor-releasing micropipette is positioned near a living neutrophil under a light microscope, and the cell migrates within the liquid chamber over time.

Evaluation guide:
(i) Target concept: Directed eukaryotic cell migration in response to a localized extracellular chemical gradient.
Minimum mechanism: Neutrophil must be viable, motile, and express functional G-protein-coupled chemokine receptors; micropipette must release diffusible chemoattractant (e.g., fMLP, IL-8) establishing a spatial concentration gradient; liquid medium must permit free diffusion and cell adhesion/motility.
(ii)Storyline: Frame 0–1: Static scene, neutrophil at rest, micropipette fixed adjacent, chamber fully visible. Frame 2–4: Neutrophil initiates polarization; leading edge extends toward pipette tip, trailing edge contracts. Frame 5–7: Sustained unidirectional translocation, entire cell advances toward tip while preserving asymmetry and texture. Frame 8–10: Final approach, leading edge contacts or nearly contacts pipette tip region; no reversal or deviation. Perspective: Fixed light-microscope top-down view; full neutrophil and pipette tip always in focus and within chamber bounds; no zoom, pan, or rotation.

Manual:
Experimental Procedure
1. Place a living neutrophil in a shallow liquid chamber under light microscope.
2. Position a chemotactic factor-releasing micropipette adjacent to the neutrophil.
3. Record 10 seconds of real-time migration under microscope.
Observation of Experimental Phenomena
Neutrophil extends a leading edge toward the micropipette tip and migrates directionally within the liquid chamber, maintaining polarized shape and granular texture.
Summary of Experimental Principles
Neutrophils detect soluble chemotactic gradients via surface receptors and migrate directionally (chemotaxis) toward higher concentrations — demonstrated here by attraction to micropipette-released factor.

Prompt Grounding rubric:
level_1: No micropipette is visible; no neutrophil is visible; no liquid chamber is visible; no migration motion is shown; none of the three core objects (neutrophil, micropipette, liquid chamber) is present.
level_2: At least one core object is present (a pipette-like shape, or a cell-like shape, or a transparent rectangular chamber), but the micropipette and neutrophil are not near each other; there is no directional movement toward the micropipette; there is no sign of a liquid environment (no meniscus, no refractive edge, no immersion appearance).
level_3: All three core objects are present: a neutrophil (small, granular, irregularly shaped cell), a micropipette (thin, tapered glass capillary), and a liquid chamber (transparent rectangular container with a visible fluid surface or edge refraction); the micropipette sits adjacent to the neutrophil; the neutrophil's position changes continuously over time, confined within the chamber.
level_4: Every requirement for a 3-level score holds, and additionally: the micropipette's tip visibly points toward the neutrophil; the neutrophil's path runs unbroken from its starting position toward the micropipette tip, with no reversal, looping, or pause-and-jump; the chamber itself stays fully static and intact throughout the video.
level_5: Every requirement for a 4-level score holds, and additionally: the neutrophil keeps a consistent granular, phase-bright texture throughout, with no blurring, fusion, or artificial smoothing; the micropipette keeps a sharp, clean taper without distortion; the liquid chamber shows a stable meniscus and refractive edge in every frame; the identity and shape of each of the three objects stays recognizable and consistent in kind from the first frame to the last.

Scientific and Causal Correctness rubric:
level_1: The neutrophil moves away from the micropipette, stays stationary, or moves with no directional bias; the micropipette shows no visible cue of chemical release (no diffusion haze, no localized contrast, no gradient-like effect) and appears functionally unrelated to the cell's motion; the neutrophil's shape contradicts its biology, e.g., a smooth rigid sphere with uniform color.
level_2: The neutrophil shows directional motion, but not toward the micropipette tip (e.g., parallel, perpendicular, or moving away from it); the micropipette is present but shows no visual sign of chemotactic function (no localized contrast near the tip, no diffusion halo); the neutrophil's shape changes in ways inconsistent with chemotaxis (e.g., it rounds up completely, fragments, or expands symmetrically in all directions).
level_3: The neutrophil moves toward the micropipette tip persistently and in one direction across the observable frames; it shows a polarized shape during migration (a leading edge extended toward the pipette and a narrower trailing region) or at minimum a clear front-to-back asymmetry oriented toward the tip; the micropipette tip stays fixed near the neutrophil throughout; nothing biologically contradictory occurs (no cell division, no lysis, no phagocytic event).
level_4: Every requirement for a 3-level score holds, and additionally: the neutrophil keeps a granular, phase-dense cytoplasmic texture throughout its motion rather than smoothing into an undifferentiated blob; its motion looks like directed crawling rather than an unrelated pattern (no ciliary beating, no pulsation disconnected from the direction of travel); the region around the micropipette tip shows a subtle, consistent visual cue (a faint diffusion haze or soft contrast change) suggesting the release of a chemical attractant; the neutrophil's path toward the tip stays plausible, without overshooting past it or curving around it unnaturally.
level_5: Every requirement for a 4-level score holds, and additionally: the neutrophil's leading edge visibly stays oriented toward the micropipette tip for the entire approach, without swinging noticeably off-target at any point; its trailing edge fully retracts with no leftover trailing material; the tip's visual cue stays localized to the immediate area around the micropipette rather than spreading to brighten the whole chamber; the neutrophil's shape changes gradually through deformation rather than snapping instantly or translating as a rigid, undeforming body.

Spatiotemporal Consistency rubric:
level_1: The neutrophil teleports between non-adjacent positions; the micropipette jumps location or rotates abruptly; the chamber's geometry distorts (warping, shearing, or an impossible perspective flip); the video shows severe flicker, duplicated frames, or black frames; the lighting changes discontinuously, e.g., switching on/off, shifting color, or a shadow jumping position.
level_2: The neutrophil's motion has gaps (two or more skipped positions along its path, or at least one jump larger than its own body length); the micropipette visibly wobbles or drifts, its tip shifting by more than a tip-width between frames; the chamber's edges warp or shimmer persistently; the motion is jerky, with two or more abrupt speed changes that have no smooth transition.
level_3: The neutrophil's position advances continuously with no teleporting or gaps; the micropipette stays fixed in position and orientation with no drift or rotation; the chamber's boundaries stay geometrically stable, with no bending, scaling, or edge flicker; the implied light source and cast shadow keep the same direction, brightness, and softness throughout; nothing breaks structurally (the neutrophil never splits, the pipette never snaps, the chamber never cracks).
level_4: Every requirement for a 3-level score holds, and additionally: the neutrophil's motion starts gradually rather than jumping instantly to full speed, and it slows or settles as it nears the micropipette tip rather than stopping abruptly; the micropipette tip shows no visible trembling; the chamber's meniscus or refractive edge stays steady with no rippling or pulsing.
level_5: Every requirement for a 4-level score holds, and additionally: the neutrophil's whole body moves as one coherent shape with no part of it shearing or moving independently; the micropipette's tip stays sharp and its taper shape stays consistent across every frame; the chamber's optical properties (refraction, edge clarity) stay identical throughout; there is no inter-frame temporal inconsistency at all: no duplicated frames, no dropped frames, and no unexplained change in exposure or brightness.