Human Glycoprotein Immunoglobulin G (IgG) is not part of drug testing/validity testing protocols. Labs practicing in the US are prohibited from performing any type of genetic testing on urine samples collected for a drug test, unless the donor gives written authorization on an entirely seperate and detailed consent form. The donor can refuse to sign such a form without facing any sort of sanction, under the Genetic Information Nondiscrimination Act (GINA).
Genetic testing is also very costly and complicated in process and because of this, coupled with the reinforcement of the GINA Act in 2008, dont expect your employer to produce such a consent form. And in lieu of reinforcement of the Act, nearly all online medical distributorships have since withdrawn the IgG dipstick from the market.
The labs can only test for drug metabolites, creatinine, pH, specific gravity, certain oxidants, the presence of pyridine and glutaraldehyde, and excessive nitirites.

There are many posts throughout the drug testing forum that discuss this issue. The Search button is your friend. :thumbsup: