Pursuant to Agriculture and Markets Law, section 57, no person shall prepare or test milk samples to determine the amount of a component or components contained therein, where the result of such test is used as a basis for payment for such milk or for the purpose of official inspection or for public record or is used to calibrate electronic instruments, unless licensed by the commissioner. A person who holds a tester's license shall have the authority to conduct the activities for which a milk receiver's license is required.