Factual error: In a number of episodes people are shown eating and drinking in the laboratories. For instance, in "Miss Willows' Regrets" Nick and Greg are seen eating fried chicken in the lab, and in "Overload" Sara eats a sandwich while watching Grissom experiment with her deli pickle. There are other examples. No reputable laboratory (which this is supposed to be) would allow its staff to eat or drink while in the lab. It is basic scientific protocol to prevent contamination of samples or the person picking up toxins on their food.
Factual error: The CSI doesn't prioritize cases by importance, and have samples from big cases go first like they do on the show. They don't have the lab in house like on the show. It's too expensive. They have to send samples from even the most important cases, to labs where it takes weeks to months to test DNA to keep down costs. They also have to do this to make sure DNA testing is done correctly. DNA has to be tested multiple times because mistakes can be made.
Suggested correction: This entry is half correct and half incorrect. It is true that DNA is not as accurate as the show depicts and no lab would run it one time. However, some CSIs do have a lab "in house" as in some units that's their "office" so to speak. Not true of all of them, but is for some. While law enforcement won't openly admit this; they do put a rush sometimes on high profile cases as they have a reputation to maintain and it won't look good to the public if results aren't coming back quick enough.
