I have read a few times that it is against the law for pre-employment drug screening can not test for gender, like testing the urine if it is male or female. Is this correct?
Thats right. Donors facing an employment-related U/A are protected against genetic profiling, under the Genetic Information Nondiscrimination Act (GINA). With that being pointed out, any human urine can be used as a sub as long as the sub donor is indeed drug-free and not overhydrated.