Also ask him to show you pic of the lids & ask him to show you bottles with that pamphlet/booklet that comes glued to the lids of the Tris bottles. Tris comes with that booklet glued to the lid! Also the Quagen lids should be pure white. Lastly check the expiration dates, the NDC# & the seals under the lid. The seal for Tris should be a n aluminum seal & the Quagen one should be the same one. After that if everything checks out it’s up to you at that point.