Domain: Healthcare — Clinical Laboratory Science
Target concept: Serum Urea Determination (Diacetyl Monoxime Method)

Video generation prompt: Take 50 μL of serum from a patient with elevated urea levels, add 2 mL of diacetyl monoxime reagent, mix thoroughly, and heat in a boiling water bath for 10 minutes. After cooling, observe the color change of the solution and compare it with the standard tube.

Evaluation guide:
(i) Target concept: Visual verification of urea-dependent chromogenic reaction via DAM method.
Minimum mechanism: Serum must contain urea; diacetyl monoxime reagent must be present and acidified; thermal energy must be applied to drive condensation reaction; resulting chromophore must be stable and spectrally distinct from unreacted reagent.
(ii)Storyline: [Frame 0–2s] Pipette draws serum from labeled clinical tube → [2–3s] Pipette dispenses into clear test tube containing amber reagent → [3–4s] Tube is mixed (vortex/inversion motion visible) → [4–7s] Tube immersed in actively boiling water bath (steam rising continuously) → [7–8.5s] Tube removed and placed on bench; condensation forms on exterior → [8.5–10s] Two tubes (test and standard) appear side-by-side under fixed frontal view; test tube shows uniform pink-red, standard tube pale yellow; no camera movement, no lighting shift, no occlusion.

Manual:
Experimental Procedure
1. Draw 50 μL serum using calibrated pipette.
2. Add to 2 mL diacetyl monoxime reagent in test tube.
3. Mix thoroughly by vortex or inversion.
4. Place tube in boiling water bath for 10 min.
5. Cool to room temperature.
6. Compare test tube color side-by-side with standard tube.
Observation of Experimental Phenomena
Test tube develops uniform pink-red color; standard tube remains pale yellow. Color difference is sharp and stable under uniform lighting.
Summary of Experimental Principles
Urea reacts with diacetyl monoxime under acidic, high-temperature conditions to form a pink-red chromophore (diazine derivative); intensity proportional to urea concentration.

Prompt Grounding rubric:
level_1: No serum sample, no diacetyl monoxime (DAM) reagent, no boiling water bath, and no side-by-side tube comparison appear anywhere in the video; none of the core objects (serum-filled tube, DAM reagent container, water bath, standard tube) are ever shown.
level_2: Only one or two core objects appear (for example a generic tube or clear liquid is shown), but serum is never visually distinguishable from plain water, the DAM reagent is never seen being added to a tube, no water bath with active heating is shown, and no second (standard) tube ever appears next to the test tube.
level_3: All four core objects appear at some point (a serum-containing tube, the DAM reagent, a boiling water bath with the test tube immersed in it, and a second standard tube placed beside the test tube in the last frame), but the sequence is out of order, e.g., the tube sits in the water bath before the reagent is ever added, or the two tubes are shown side-by-side before any heating occurs.
level_4: All four core objects appear and are visually distinguishable by color and context alone (serum is faintly yellow-tinged rather than water-clear; the DAM reagent is a visibly amber liquid in its own container; the water bath shows active bubbling with the test tube immersed; the standard tube is clearly a separate, adjacent tube), and the steps occur in the correct order (serum transfer, reagent addition, mixing, heating, cooling, then side-by-side placement) with no tube disappearing, duplicating, or swapping places.
level_5: Every core object is unambiguous from color and context alone (serum drawn from a red-topped or similarly distinct clinical tube; DAM reagent visibly amber inside its container; water bath shows continuous, vigorous bubbling with the tube fully submerged; cooling is visually implied by condensation forming on the tube's outer surface), the six-step sequence (serum transfer, reagent addition, mixing, heating, cooling, side-by-side placement) proceeds in order with no step skipped or repeated, and the final frame shows the test tube and standard tube placed side-by-side within one continuous, fixed camera view with no cuts or perspective changes. The specific colors each tube reaches are not evaluated here.

Scientific and Causal Correctness rubric:
level_1: No color change happens at all, or the solution turns a color inconsistent with urea-DAM chemistry (blue, green, black, or brown) either before or after heating; the boiling-water-bath heating step is skipped entirely, or the test tube is never compared against the standard tube.
level_2: A color change occurs but violates the expected chemistry: the test tube turns pink-red before heating even begins, or it only reaches a faint yellow/orange after heating instead of pink-red, or the standard tube develops the same reaction color as the test tube, or heating is shown but no color ever develops afterward.
level_3: The test tube turns pink-red only after heating, and the standard tube stays pale yellow or colorless, with no color appearing before heating begins; however, either the pink-red looks about as faint as the standard tube's yellow (too little contrast between the two), or the pink-red appears to form while the tube still looks like it just came straight out of the boiling bath, with no cooling cue shown first.
level_4: The test tube turns pink-red only after both heating and an implied cooling period, the standard tube stays a consistent pale yellow throughout, the two colors are clearly distinguishable from each other during the side-by-side comparison, and no unrelated tube, bottle, or bubble in the shot picks up a stray pink-red tint. The video visually supports serum urea plus DAM reagent plus heat producing the pink-red chromophore.
level_5: The test tube reaches a solid, even pink-red with no cloudiness, streaking, or floating particles, while the standard tube is an even pale yellow with a matching liquid level and meniscus shape; the color difference between the two tubes is obvious at a glance under normal lighting; no reagent bottle, pipette, or background object ever picks up a pink-red tint; the color outcome matches what the diacetyl monoxime urea reaction should produce and nothing else.

Spatiotemporal Consistency rubric:
level_1: The test tube instantly jumps from one location or state to another between frames: for example it is on the bench in one frame and already sitting in the boiling water bath in the next with no motion shown in between; reagent appears inside the tube before any pipette or pour is shown; steam is visible before the water bath is ever shown heating; the tube's color switches on and off instead of developing gradually; or the room lighting abruptly flips between bright and dark from one shot to the next with no in-scene cause.
level_2: The mixing motion (swirl or inversion) stutters or stops and restarts rather than flowing continuously; the tube sits in the water bath for the stated heating time but no steam, bubbling, or other visual cue shows time actually passing; the test tube's position or angle changes noticeably between the pre-heating and post-heating shots even though it was never shown being moved; or the pink-red color appears the instant the tube leaves the water bath with no cooling period shown at all.
level_3: Small continuity issues remain: brief unsteadiness in the hand or arm during the serum draw, a moment where a hand or the tube's edge briefly blocks the view of the liquid during mixing, or a short flicker in the room lighting during the heating shot; the tube's position on the bench shifts only slightly (less than about 10% of the frame width) between the pre-cooling and post-cooling frames; the overall step order is correct, but cues like condensation gradually forming or steam tapering off as heating ends are missing.
level_4: Every action reads as one continuous, physically sensible motion: the pipette tip dips into the serum and liquid visibly rises up the pipette before it moves to the tube; the DAM reagent pours in as a steady stream rather than snapping into place; mixing shows the liquid surface actually swirling; the water bath shows a steady rhythm of rising bubbles and steam through the whole heating shot; cooling is shown by a ring of condensation gradually forming on the tube's exterior; the tube never jumps position, and the room lighting stays the same from one shot to the next.
level_5: The pipette tip visibly touches the serum before any liquid is drawn up; the serum finishes transferring into the reagent tube before the mixing motion starts; the mixing swirl runs smoothly for its full duration without stopping partway; steam rises continuously and evenly from the water bath for the entire heating shot; condensation builds up gradually on the tube from top to bottom during cooling; in the final side-by-side frame both tubes appear at the same size, angle, and camera distance as each other; every motion in the video flows smoothly from frame to frame with no sudden jumps, stutters, or warping of the tubes or liquids.