Domain: Healthcare — Basic Immunology
Target concept: Antibody-Antigen Agglutination Reaction of Colored Latex Microspheres in a Test Tube

Video generation prompt: Two transparent test tubes containing red latex microsphere suspensions are placed side by side on the experimental bench. Using a dropper drawn from a bottle labeled "Antibody," antibody solution is added to the left tube; using a separate dropper drawn from a bottle labeled "Saline," physiological saline is added to the right tube. The tubes are then gently inverted to mix and allowed to stand.

Evaluation guide:
(i) Target concept: Antibody-antigen specific agglutination mediated by colored latex microspheres in controlled buffer conditions.
Minimum mechanism: Red latex microspheres must be antigen-coated; antibody must be bivalent and specific to that antigen; physiological saline must be inert (no cross-linking capacity); agglutination requires lattice formation, not simple sedimentation.
(ii)Storyline: [Frame 0–2] Two identical red-suspended tubes side-by-side on bench → [Frame 3–4] Distinct reagent delivery: a dropper drawn from a bottle labeled "Antibody" delivers solution into the left tube; a separate dropper from a differently labeled "Saline" bottle delivers solution into the right tube; two visually distinguishable containers, not the same dropper reused → [Frame 5–6] Synchronous gentle inversion of both tubes (full 180° arc, no spill) → [Frame 7–10] Tubes returned upright and held still; left tube develops persistent red clusters; right tube retains uniform red dispersion; all events occur from fixed frontal viewpoint with full tube visibility and no occlusion.

Manual:
Experimental Procedure
1. Place two transparent test tubes side by side on the bench; both filled with red latex-microsphere suspension.
2. Using a dropper drawn from a bottle labeled "Antibody," add antibody solution to the left tube; using a separate dropper from a bottle labeled "Saline," add physiological saline to the right tube.
3. Gently invert each tube once to mix; then stand both tubes upright and observe.
Observation of Experimental Phenomena
Left tube: red particles form visible macroscopic aggregates (agglutination). Right tube: red particles remain evenly dispersed (no agglutination).
Summary of Experimental Principles
Antibody binds specifically to antigen-coated latex microspheres, forming cross-linked lattices that precipitate as visible clumps. Physiological saline provides isotonic control — no binding, thus no agglutination.

Prompt Grounding rubric:
level_1: Neither test tube is visible, or only one appears; neither tube shows a red latex-microsphere suspension; the two reagent-delivery devices (droppers/bottles) are never shown or are visually identical with no way to tell which liquid goes into which tube; or the two tubes are never shown together in the same shot on the bench.
level_2: Both test tubes appear together on the bench, each holding a red suspension, but the reagent-delivery step is missing, ambiguous, or misattributed, for example, the same dropper is used for both tubes with no distinguishing label or bottle color, a liquid is added off-screen with no visible link to a specific tube, or the tubes are not actually resting on the bench surface as the setup describes.
level_3: Two transparent test tubes sit side by side on the bench, each holding a red latex-microsphere suspension; a dropper drawn from a bottle labeled (or otherwise visually marked as) "Antibody" delivers solution into the left tube; a separate dropper from a differently labeled or differently colored "Saline" bottle delivers solution into the right tube; both additions happen before either tube is inverted, and neither tube receives the wrong reagent.
level_4: Everything required at level 3 holds, and in addition, both tubes are gently inverted through a full upward-and-downward arc after their respective reagent is added and before the standing period begins; no tube is only shaken or stirred instead of inverted, and no tube skips the inversion step.
level_5: Everything required at level 4 holds, and in addition, both tubes stay upright and undisturbed on the bench for a clearly extended standing period after inversion, with no premature handling, removal from frame, or further shaking; the full standing sequence is shown from a single unobstructed, unblurred view of both tubes together, without asserting which tube's contents end up clumped versus dispersed, which is a scientific-outcome judgment scored separately.

Scientific and Causal Correctness rubric:
level_1: The red latex suspension in both tubes still looks identical and unchanged in appearance after standing: neither tube shows clusters and neither shows any other visible transformation; or the suspension turns a different color entirely, goes cloudy/opaque, or turns black; or visible clumping shows up in both tubes or in neither tube; or clumps are already visible before the reagents are even added or while they are still being added.
level_2: Both tubes still look like plain red suspensions at the start, but after standing there's no visible difference between them; or clumping shows up in the right (saline) tube instead of the left; or the left tube merely settles into a uniform layer at the bottom rather than forming distinct clumps; or clumps appear in a tube before the antibody has actually been added to it.
level_3: After standing, the left tube shows distinct, visible clumps of red particles (clearly separated aggregates rather than an even haze or a settled layer), while the right tube's red particles stay evenly spread through the liquid with no macroscopic clumps forming; both of these states appear only after standing begins and persist for the rest of the observation.
level_4: Everything required at level 3 holds, and in addition, the clumps in the left tube form only after the antibody has been added and the tube has stood for a while, never right after the antibody drop lands or during the inversion itself, and the right tube's apparent uniformity is not an illusion created by air bubbles, dust, or streaks that merely look like clumps.
level_5: Everything required at level 4 holds, and in addition, the clumps in the left tube look irregular, loose, and porous, like a flocculent network of aggregated particles, rather than a single dense pellet or sharp crystal-like precipitate, while the right tube stays fully translucent with an even red color and no particles settling out or forming layers at all, matching what specific antibody-antigen cross-linking should look like next to an inert saline control.

Spatiotemporal Consistency rubric:
level_1: A test tube drops out of frame entirely partway through the video and then reappears afterward in a new position or tilt with no camera movement to explain it; the scene cuts abruptly from bright to dark lighting with no visible transition; a tube wall bends, distorts, or loses its transparency partway through; or the red suspension flickers in and out, or its density jumps abruptly, between adjacent frames.
level_2: Both tubes stay in the same place, but the inversion motion is so blurred that it's unclear which tube is which or what's inside; the inversion itself is jerky, with more than one visible pause or stutter; or the camera unexpectedly pans, zooms, or moves during the standing phase when it should be static.
level_3: The left tube and right tube stay exactly where they were set down on the bench relative to each other, from the first frame to the last, with neither one vanishing, warping into a different shape, or cracking apart on its own; each tube's inversion reads as one continuous, smooth arc rather than a series of disconnected poses; and once the tubes are set down to stand, they remain still and visible in the same spot for the rest of the video.
level_4: Everything required at level 3 holds, and in addition, both tubes complete their inversion at essentially the same time as each other (their start and end points visibly line up), the relative positions of the two tubes to one another never shift during the motion, and the red particles inside never blink or flicker in and out of view between frames.
level_5: Everything required at level 4 holds, and in addition, the tubes' glass walls look physically plausible throughout, never turning opaque or showing impossible internal reflections, and the pacing of the video feels physically consistent: the inversion takes a natural couple of seconds rather than appearing sped up or slowed down relative to the standing period that follows.