Domain: Healthcare — Clinical Laboratory Science
Target concept: Lipid Cholesterol Testing (Cholesterol Oxidase Method)

Video generation prompt: Take 30 μL of serum from a patient with elevated lipid cholesterol, add 1.5 mL of cholesterol reagent, incubate at 37°C for 10 minutes, observe the color change of the solution, and measure the absorbance using a spectrophotometer.

Evaluation guide:
(i) Target concept: Enzymatic colorimetric quantification of serum cholesterol via cholesterol oxidase method.
Minimum mechanism: Serum must contain measurable cholesterol; reagent must contain cholesterol oxidase, peroxidase, and chromogen; incubation at 37°C enables enzymatic kinetics; color development requires stoichiometric reaction completion; absorbance measurement requires optical path integrity and stable chromophore.
(ii)Storyline: [Frame 0–2] Serum vial and reagent tube side-by-side on lab bench; pipette approaches vial → [Frame 3–4] pipette tip enters vial, aspirates → [Frame 5–6] pipette lifts, moves horizontally to reagent tube → [Frame 7–8] tip enters tube, dispenses → [Frame 9–12] tube placed in labeled 37°C incubator; static for full duration → [Frame 13–15] tube removed, mixture transferred to cuvette → [Frame 16–18] cuvette inserted into spectrophotometer → [Frame 19–20] display shows stable pink-red solution and numeric absorbance; all events occur from fixed frontal bench-level viewpoint; no cutaways, zooms, or POV shifts; all objects remain fully visible and unoccluded.

Manual:
Experimental Procedure
1. Pipette 30 μL serum from patient sample vial.
2. Dispense into 1.5 mL cholesterol reagent tube.
3. Mix gently, place tube in 37°C incubator for 10 min.
4. Transfer mixture to spectrophotometer cuvette and measure absorbance.
Observation of Experimental Phenomena
Solution changes from colorless/pale yellow to uniform pink-red after incubation; absorbance value displayed on spectrophotometer is non-zero.
Summary of Experimental Principles
Cholesterol oxidase in reagent oxidizes cholesterol → produces H₂O₂ → reacts with peroxidase and chromogen → forms pink-red quinoneimine dye; absorbance proportional to cholesterol concentration.

Prompt Grounding rubric:
level_1: No serum sample, no cholesterol reagent tube, no pipette, and no spectrophotometer are visible; no liquid transfer from vial to tube occurs; no incubation step is shown; and no color observation or absorbance reading is implied.
level_2: At least one correct object is present (for example, the pipette or the reagent tube), but the serum and reagent are both missing or mislabeled; the transfer action is missing or is applied to the wrong objects; the incubation and measurement steps are both left out entirely.
level_3: The serum vial (a clear liquid in a small vial), the cholesterol reagent (in a larger tube), the pipette, and the spectrophotometer are all present; liquid is transferred from the serum vial into the reagent tube; a static incubation period is implied by the tube sitting in a labeled 37°C environment or next to a timer; a final absorbance measurement is implied by the spectrophotometer's display or by a hand positioning the cuvette near the instrument's slot.
level_4: All objects are present and clearly distinguishable: a small serum vial with clear liquid, a larger labeled cholesterol reagent tube, a pipette shown drawing up 30 μL, a clearly indicated 37°C incubation environment (water bath or incubator label), and a spectrophotometer with a cuvette inserted and its display active; the pipette tip visibly enters the serum vial, then dispenses into the reagent tube; no extra objects or actions are shown.
level_5: All objects are present, correctly sized, and spatially coherent: the serum vial sits next to the reagent tube on the same bench; the pipette is held upright while drawing up serum and tipped for dispensing; the tube is placed inside a labeled 37°C incubator (or water bath) for one continuous static period; the cuvette is visibly filled with the reaction mixture and inserted into the spectrophotometer; the display shows a numeric absorbance value; nothing in the scene looks out of place for a clinical chemistry bench.

Scientific and Causal Correctness rubric:
level_1: The serum-and-cholesterol-reagent mixture stays colorless or pale yellow through the entire incubation and measurement window, with no shift toward pink-red at any point; or a pink-red tint appears without the serum and reagent ever having been combined; or the color has no visible connection to the mixing or incubation steps.
level_2: A color appears but is the wrong hue for this reaction: blue, green, or deep red instead of pink-red; or the pink-red tint is already present before the reagent has been added to the serum; or an absorbance reading is shown while the cuvette still holds a colorless liquid.
level_3: After the serum and cholesterol reagent are combined, the liquid shifts from colorless or pale yellow to a pink-red hue; the color is spread evenly through the liquid rather than sitting as a patch or streak; the color change happens during the static incubation period, not before mixing or after the tube is removed; any absorbance reading shown comes only after this color has developed.
level_4: The liquid shows no pink-red tint before mixing and none in the moments right after mixing; the pink-red color only becomes visible once the full 10-minute, 37°C incubation has elapsed, as shown by a timer or label; the depth of color looks the same from the top of the liquid column to the bottom; the absorbance value on the spectrophotometer display is a clearly non-zero, positive reading (for example, above 0.1), consistent with the elevated cholesterol described in the prompt.
level_5: The sequence reads as fully causal: clear serum is drawn up by the pipette and dispensed into the cholesterol reagent tube; the tube sits undisturbed while a pink-red hue builds evenly and progressively through the full incubation; the fully developed pink-red color is still intact, unfaded and unseparated, when the mixture is transferred to the cuvette and measured; the spectrophotometer then shows a steady, non-zero absorbance value; the color never appears too early, too late, patchy, or cloudy.

Spatiotemporal Consistency rubric:
level_1: The serum vial or the 1.5 mL cholesterol reagent tube swaps position on the bench, or is missing from a shot, with no pipette or hand action explaining the change; the pipette's sample is shown already inside the reagent tube before it has ever touched the vial; the pink-red color appears as an instantaneous flash with no visible transition from the colorless starting liquid; or the 37°C incubator's timer display jumps backward or restarts partway through the incubation shown.
level_2: The pipette tip is not aligned with the vial or tube opening in a frame where liquid is clearly moving; the reagent tube's liquid level rises with no dispensing motion visible from the pipette; the pink-red tint shows up in one frame and is completely gone in the next with no fading in between; or the tube's spot on the bench shifts between the mixing shot and the incubation shot with no hand having moved it.
level_3: The serum vial and the reagent tube stay in the same relative spot on the bench across the pipetting, incubation, and measurement shots; the pipette follows one continuous, visible path from the vial to the tube; the pink-red color spreads as one even tint through the whole volume of liquid rather than pooling in one spot or fading in and out; the incubator or timer indicator only moves forward, never resetting; the spectrophotometer stays in the same place and orientation throughout.
level_4: Everything above holds, and in addition the pipette barrel keeps a constant width and does not appear to bend between the aspirate and dispense shots; the liquid surface in the vial and the reagent tube stays a smooth, steady curve instead of flickering or jumping; the pink-red color deepens at a visibly similar rate across the entire liquid at once (never as a front rising from the bottom, a patch spreading from one wall, or a streak), matching the fact that the cholesterol oxidase, peroxidase, and chromogen were already mixed evenly through the serum before the color forms; the cuvette's outline lines up with the spectrophotometer's insertion slot in every frame it appears.
level_5: The pipette's motion from aspirating at the vial to dispensing into the tube has no gap that would hide where the tip is; the tube's color change reads as one continuous, whole-volume darkening from pale yellow toward pink-red, with no single frame showing part of the liquid noticeably darker than the rest; the 10-minute, 37°C incubation is shown as one unbroken static hold, with any on-screen timer or label only counting upward; the transfer into the cuvette and the cuvette's seating in the spectrophotometer line up cleanly across every frame that shows it; no bench object (vial, reagent tube, pipette, cuvette, or spectrophotometer) changes position, size, or shape without a matching hand action.