Here is my experience with the lab.

1. My daughter was tiny (less than 5lb at the time)  when she was 4 days old. It was VERY difficult to draw blood from her. I was holding her when they tried to draw blood from her and I could not stop crying. They stuck her at least 5 or 6 times before they finally got someone from NICU who made it. Guess what, they put the blood in the wrong tube !!! The sample was wasted.  The worst part was that they lied to me. They came to me the next day and asked to draw blood again (my daughter was in the hospital at the time). I asked them why, they did not tell me they made a mistake. They said they needed to do it again. Later my endo told me what happened and I was so pissed off.

2.  It happened 3 times at our local hospital when they sent the sample to Esoterix. It should be 17OH Progesterone but they sent for 17OH Pregnenolone. We were lucky that when our endo called Esoterix, they had some sample left which was enough to run 17OHP. 

Now I print out a note which reminds them it is 17OH Progesterone NOT 17OH Pregnenolone and bring it with me everytime . I give it to the lab staff and ask them to make sure it is right. Also I pay attention to the tubes they use to collect the sample. It should be red for 17OHP/testosterone and delta4, purple for PRA. I also double check by asking them what we are testing and how many ml we need.

Good luck