Animal dander would be the answer you're looking for.
Hope this helps :)
I believe it is gel electrophoresis.
Gel electrophoresis is a techniwue used to separate DNA fragments or other macromolecules such as RNA and proteins based on their size and charge. It can also determine the actual size of a piece of DNA by examining it next to a standard "yardstick" made up of DNA fragments of known sizes.
Answer:
used in an experiment as a way to ensure that your experiment actually work
Explanation:
The answer is definitely B
