I've been to two other LabCorp offices in SF and didn't leave with a very good impression. Some of the people were very nice, some were very rude. The offices didn't look too clean and sometimes the people drawing the blood really didn't seem to know how to stick a needle into a vein. But that was several years ago. This time, because the form a doctor gave me said LabCorp at the top I decided to go to the one at 2100 Webster. I figured that being in the CPMC facility, this LabCorp would be everything that the others weren't. Everything looked clean and everyone I dealt with was very nice. but... Now, I'm not the type of person who usually gives much thought to having a little blood drawn. A pin prick when the needle is inserted and that's about it. But this time, the needle insertion was very painful and the pain didn't let up the whole time it was stuck in my arm. I've never had that happen before. Also, some other reviewers here have left photos of large bruises on their arms. Their arms looked good compared to mine. My bruise (the same intense coloring of a very bad black eye) is 2.5 inches long, 1.75 inches wide and has a very well defined raised lump about 5/8 inch diameter in the center. There isn't any pain and after about a week the bruise is starting to subside (the raised lump is still there). I'm not worried about it, but next time I won't be going to another LabCorp office. Most medical facilities have a lab where blood is drawn and LabCorp (4th floor) isn't the only one in the 2100 Webster, CPMC building. read more