Domain: Healthcare — Basic Immunology
Target concept: Complement-Mediated Hemolysis (Simulated)

Video generation prompt: Prepare a test tube, add sheep red blood cells, then add a specific anti-sheep red blood cell antibody, followed by fresh serum as a source of complement. Gently mix and incubate briefly. Use a pipette and test tube to clearly demonstrate the sequential addition and mixing process.

Evaluation guide:
(i) Target concept: Complement-mediated hemolysis requires antibody-dependent activation of fresh complement to lyse target RBCs.
Minimum mechanism: Antibody must bind SRBCs *first*; fresh (non-heat-inactivated) serum must be added *second*; mixing enables complement assembly; lysis manifests as irreversible, uniform hemoglobin release into supernatant — not agglutination, not oxidation, not mechanical rupture.
(ii)Storyline: Frame 1–2: Empty test tube centered; pipette enters from top-right. Frame 3: SRBCs dispensed → immediate pellet formation at bottom. Frame 4: Antibody dispensed → no pellet disturbance. Frame 5: Serum dispensed → no pellet disturbance. Frame 6: Pipette withdraws; tube begins smooth 180° inversion. Frame 7: Tube held inverted → pellet loosens. Frame 8: Tube returned upright → supernatant clears and diffuses pink-red upward. Frame 9–10: Fully homogeneous pink-red translucent liquid; no pellet remnants. All actions occur from fixed frontal viewpoint; no cutaways; no zoom; critical regions (pellet, meniscus, supernatant) remain fully visible throughout.

Manual:
Experimental Procedure
1. Place empty test tube upright.
2. Use pipette to add sheep red blood cells (SRBCs) — forms red pellet.
3. Use same pipette to add anti-SRBC antibody — no visible change.
4. Use same pipette to add fresh serum — no immediate change.
5. Gently invert tube once to mix — observe hemolysis.
Observation of Experimental Phenomena
Red pellet disperses; supernatant turns uniformly pink-red and translucent; no clumps or sediment remains.
Summary of Experimental Principles
Antibody binds SRBCs → activates classical complement pathway → membrane attack complex forms → RBC lysis → hemoglobin release → pink-red hemolyzed supernatant.

Prompt Grounding rubric:
level_1: No test tube is visible, no sheep red blood cell (SRBC) suspension appears, and no antibody or serum liquid is added by pipette; none of the four required elements (test tube, SRBC suspension, antibody, serum) can be identified anywhere in the scene.
level_2: Only one of the four elements appears (for example, an empty test tube with nothing added), and no addition or mixing sequence is shown; or two elements appear but in implausible containers (e.g., the SRBC suspension shown in an open dish instead of the tube, or a reagent poured from a bottle instead of a pipette).
level_3: The test tube, a settled red SRBC suspension inside it, and two further liquids representing the antibody and the serum are all added by pipette; the antibody and serum liquids are visually distinguishable from each other and from the red suspension (by color, clarity, or by clearly separate pipette actions); the general order (SRBCs first, then antibody and serum) is at least partly visible; some gentle mixing occurs by the end.
level_4: Everything described for level 3 is present. The antibody and serum liquids remain visually distinct from one another throughout (so a viewer can tell two different reagents were used, not one reagent added twice); the SRBCs settle first, then the antibody, then the serum, in that order; a single gentle inversion or slow swirl (not vigorous shaking) follows the serum addition; no reagent is swapped for an implausible substitute mid-scene (e.g., a solid object or an obviously wrong-colored liquid standing in for the antibody or serum).
level_5: Building on level 4, the tube stays in the same fixed position and orientation on the bench except for the single controlled inversion used to mix the antibody and serum with the SRBCs, with no other drifting, tipping, or repositioning; the SRBC suspension settles into a visible pellet before either the antibody or serum is introduced; the antibody and then the serum are each dispensed from a pipette that never touches the tube's inner wall; the single gentle mixing motion (the inversion) happens only after both the antibody and serum have been added; if any labels or text appear on screen, they are legible and not contradictory.

Scientific and Causal Correctness rubric:
level_1: The red SRBC suspension stays uniformly opaque or remains a sharp, settled pellet for the whole clip; the liquid above it stays clear or pale and never turns pink-red; nothing resembling hemolysis (a color change or clearing of the pellet) appears at any point.
level_2: The liquid turns uniformly red without ever first showing a settled SRBC pellet (so the change can't be told apart from just stirring a red liquid); or the pellet clears and the liquid above it turns pink-red before the serum is added; or a color change happens with no visible antibody or serum addition beforehand.
level_3: Before the antibody or serum goes in, the SRBCs sit as a settled, opaque pellet at the tube's bottom; only after both have been added and the tube is mixed does the liquid above the shrinking pellet turn pink-to-red and translucent; there is no greenish or brown discoloration, no clumping, and the color change never happens before the serum is added.
level_4: Building on level 3, adding the antibody causes no visible change to the pellet, and adding the serum also causes no immediate change; only after the mixing step does the liquid above progressively turn pink-red while the pellet visibly shrinks or disappears, with no leftover clumps, streaks, or off-color tint.
level_5: Building on level 4, the clearing of the pellet and the reddening of the liquid above it read as one continuous, connected process spreading upward from where the pellet was, rather than the whole tube changing color all at once; by the end of the clip the liquid is a uniform translucent pink-red with no visible pellet, streaks, or layering left.

Spatiotemporal Consistency rubric:
level_1: The test tube vanishes from view and reappears elsewhere in the frame, or the pipette carrying the SRBCs, antibody, or serum jumps to a new position with no motion shown getting there, or the tube's shape suddenly bends or breaks with no cause, or the background behind the tube swaps or warps between shots.
level_2: There is one clear break in continuity: for example the pipette appears already holding the antibody or serum with no earlier shot of it being drawn up, or the SRBC suspension appears already inside the tube in one frame after the tube was empty the frame before with no visible pour, or the final mixing motion starts mid-inversion instead of building up from rest.
level_3: The tube stays in the same general position and orientation across the clip; the pipette approaches from the same side each time it is used to add SRBCs, antibody, or serum; each liquid enters the tube from the pipette tip rather than appearing out of nowhere; nothing in the scene flickers or swaps identity mid-action; small imperfections are fine, such as a brief moment where a hand blocks part of the pipette.
level_4: In addition to level 3, the tube does not drift or tip over between the SRBC, antibody, and serum additions; the pipette's approach path stays consistent throughout (same angle, same side); the mixing motion is a single smooth, continuous action rather than several disconnected jerks; and no part of the setup doubles, disappears, or deforms between frames.
level_5: In addition to level 4, the tube's position and the camera's framing show no visible drift or shift from the first frame to the last; the pipette's path from entry to withdrawal reads as one unbroken motion for each addition; each liquid's entry into the tube shows a visible meniscus rather than an instant color swap; and the final mixing motion stays fully contained within the tube with no sudden jump in the liquid's fill level.