What is true about anti-human serum globulin reagent?
1. Occurs naturally in most humans
2. Is produced in laboratory animals
3. Never detects complement-dependent antibodies

The anti-human serum globulin reagent is produced in laboratory animals. These are used to test the absence or the presence of red-blood cell antibodies that which are not usually expected. Laboratory animals are usually used to carry out experiments and medical tests, because the way their bodies work closely resemble the human body on the most basic level. In general, laboratory animals include rabbits, mice, monkeys, cows, pigs, etc.

Experiments like these are carried out in a fully controlled environment by a team of specialists, and they are done to study the effect that which any particular stimulus could have on other animals or humans.