Answer:
True.
Step-by-step explanation:
The principle of the luminol test is to reveal these traits with a light-generating chemical reaction between various chemicals and hemoglobin, the oxygen-carrying protein in the blood. Molecules break down and atoms rearrange to form different molecules. In this particular reaction, the reactants (original molecules) have more energy than the products (resulting molecules). Molecules get rid of the extra energy in the form of visible light photons. This process, commonly known as chemiluminescence, is the same phenomenon that makes fireflies and glow sticks glow.
Investigators spray luminol into a suspicious area, turn off the lights, close the curtains, and look for a green or bluish light. If there are traces of blood in the area, these lights will appear.
The problem with luminol is that the chemical reaction can destroy other evidence at the crime scene and interfere with later DNA testing of blood. For this reason, researchers only use luminol after exploring the other options.