Hey guys, Id like to give you guys a heads up on this one. I just recently took a drug test for employment. As I have done in the past, I grabbed a quick fix kit and handled my business, i get a call a couple days later from the employer saying it was diluted. I decided to contact the manufacture. They told me a few things that you guys might want to know: 1) if you purchase a quick fix kit from an outside vendor, you need to call in and verify that the batch is still good. (I never knew this) the batch # is inside the packaging on a green slip of paper. 2) Lab Corp can reserve the right to make you retest without even testing your per due to color or "lack of foam". (If you didn't get paperwork saying that your sample was diluted, you probably had lab corp pull this same move on you) 3) I didn't use the microwave to heat up my sample (regretfully) and this may be the reason the coloration was cause for a retest. I hope this information is useful to you ladies and gents.