Domain: Healthcare — Clinical Laboratory Science
Target concept: Serum Bilirubin Test (Diazotization Method)

Video generation prompt: Take 50 μL of serum from a patient with elevated bilirubin, add 1 mL of diazo reagent, mix thoroughly, and let stand for 5 minutes. Then add 0.5 mL of alkaline tartaric acid solution and observe the color change, comparing it with a standard color chart.

Evaluation guide:
(i) Target concept: Visual confirmation of bilirubin quantification via diazo coupling, where alkaline tartaric acid shifts the initially reddish-purple azobilirubin into the blue/blue-green chromogen used for reading against a standard color chart.
Minimum mechanism: Serum must contain bilirubin; the diazo reagent must contain a pre-formed diazonium salt that couples with bilirubin during the initial mixing/standing step to give a reddish-purple azobilirubin; adding alkaline tartaric acid solution then raises the pH, converting that reddish-purple azobilirubin into a blue-to-blue-green chromogen, which is the color actually compared against the standard chart.
(ii)Storyline: [Frame 0–2] Serum is pipetted into a tube. [Frame 3–4] Diazo reagent is added, and the mixture takes on a faint reddish-purple tint after standing. [Frame 5–6] Tube is mixed (visible swirl/turbulence). [Frame 7–8] Alkaline tartaric acid solution is added, and the color visibly shifts from reddish-purple toward blue/blue-green. [Frame 9–10] The final blue-green color is held next to the standard color chart for a direct side-by-side comparison; the whole sequence is shot from one fixed frontal viewpoint with steady lighting, no cuts, no occlusion, no zoom, and the tube and chart stay visible together during the final comparison.

Manual:
Experimental Procedure
1. Pipette 50 μL of serum into a clean test tube.
2. Add 1 mL of diazo reagent, mix thoroughly by inversion or vortex.
3. Wait 5 minutes, then add 0.5 mL of alkaline tartaric acid solution.
4. Observe final color and compare side-by-side with standard color chart.
Observation of Experimental Phenomena
After the diazo reagent is added and the mixture stands, a reddish-purple tint develops; once the alkaline tartaric acid solution is added, the color shifts to a stable blue-to-blue-green hue, whose intensity corresponds to the bilirubin concentration and is matched against a specific band on the standard color chart.
Summary of Experimental Principles
Bilirubin couples with the diazotized reagent to form azobilirubin, which is reddish-purple in acidic solution. Adding alkaline tartaric acid raises the pH, converting azobilirubin into a blue-to-blue-green chromogen; reading this blue-green color against the standard chart gives a more sensitive and stable measure of bilirubin concentration than reading the initial reddish-purple color directly.

Prompt Grounding rubric:
level_1: None of the required items are shown (no serum, no diazo reagent, no alkaline tartaric acid, no test tube, no pipette, and no color chart), and no transfer, mixing, addition, or comparison action takes place.
level_2: At least one item appears (a tube or a pipette, say), but something essential is missing (serum, diazo reagent, alkaline tartaric acid, or the color chart is absent), or the order is wrong, such as the alkaline solution going in before the diazo reagent, or the mixing step being skipped entirely.
level_3: All five items appear (the serum, the diazo reagent, the alkaline tartaric acid solution, the test tube holding the reaction, and the standard color chart), and the three steps happen in the right order: serum goes into the tube first, then the diazo reagent is added and mixed, then the alkaline tartaric acid solution is added; nothing is swapped for water or another liquid.
level_4: Everything in score 3 holds, and additionally: the tube and the color chart are shown together in the same continuous shot; the mixing step is unambiguous, with visible swirling or turbulence in the liquid; each addition shows a distinct stream of liquid actually entering the tube rather than being implied off-screen; there's no duplicated tube, no extra unexplained reagent, and no tool that doesn't belong.
level_5: Everything in score 4 holds, and additionally: the serum container, the diazo reagent container, and the alkaline tartaric acid container each keep the same size, label, and color (colorless to pale yellow for both reagents) throughout; the test tube stays in the same spot with no unexplained jump; the color chart is fully legible with a graded series of hues; and every liquid addition comes from a clearly marked, calibrated pipette or dispenser rather than an unmarked syringe or dropper.

Scientific and Causal Correctness rubric:
level_1: No meaningful color change happens in the tube, or the final color is nothing like blue or blue-green (it stays colorless, or turns yellow, brown, or some unrelated color), and it's never compared against the standard chart.
level_2: Some color does appear, but not the right one: for instance it stays reddish-purple/pink instead of shifting further to blue-green after the alkaline tartaric acid is added, or it turns an unrelated color like grey or black, or a color shows up but there's no chart shown for comparison.
level_3: A reddish-purple tint appears after the diazo reagent is added and the mixture stands, and then, after the alkaline tartaric acid solution goes in, the color visibly shifts to blue or blue-green; the standard color chart is shown with a graded series of hues, and the tube and chart appear together on screen for a direct comparison.
level_4: Everything in score 3 holds, and additionally: the tube stays a faint reddish tint (not yet strongly colored) before the alkaline tartaric acid is added, and only shifts fully to blue/blue-green afterward, with the shift happening gradually rather than as an instant flash; the final blue-green settles into a stable hue that falls somewhere in the middle-to-high range of the chart.
level_5: Everything in score 4 holds, and additionally: the final hue lines up with one specific band on the chart rather than sitting ambiguously between two; the color doesn't look washed out or shift appearance under different framing; the blue-green stays even throughout the liquid column with no layering, cloudiness, or stray reflections that would make the color look different than it actually is.

Spatiotemporal Consistency rubric:
level_1: The tube suddenly appears in a different part of the shot with no motion carrying it there; a reagent bottle is missing for a stretch and then is back; the color chart pops in or out mid-sequence; the room's lighting swings from bright to dark with no transition; the liquid level jumps without any pouring motion; the mixing looks frozen or jerky, like moments are missing.
level_2: The tube shifts position noticeably between shots without anyone moving it; the lighting flickers or a shadow changes direction without explanation; the mixing motion stalls partway through and then resumes; the color chart only enters the frame after the tube's color has already developed, breaking the sense that the two are being compared honestly.
level_3: The tube, the reagent containers, and the color chart all stay in believable, consistent positions relative to each other throughout; nothing goes missing or jumps location; the lighting and shadows look the same in the early and late parts of the clip; the mixing shows a continuous swirl or vortex rather than freezing or skipping; the whole sequence plays out in one consistent setting with no jarring change of background or camera angle.
level_4: Everything in score 3 holds, and the steps happen in a believable order without overlap: the serum finishes going in before the diazo reagent starts; the diazo reagent finishes before mixing starts; the mixing clearly stops before the alkaline tartaric acid goes in; and the color only starts visibly changing after that addition is complete; nothing is shown happening at the same time as something else that should come before or after it.
level_5: Everything in score 4 holds, and the physical motion looks natural throughout: the pipette plunger moving down lines up with liquid actually leaving the tip; the mixing speeds up smoothly rather than snapping instantly to full speed; the liquid's surface behaves like a real liquid, with a believable meniscus and no floating droplets defying gravity; the pipette tip never appears to pass through the tube wall; and every motion in the clip looks smooth and bounded rather than snapping between poses.