The following event happened to me on the last weekend of September, 2003, while attending a class given by Vianna Stibal. The following experiment was done rather informally, though with good care to have fairly clear results. I believe it could be repeated in a more rigourous setting if someone chose.
In the room along with the class was a woman with a microscope doing "Live Blood Cell Analysis". The microscope also had a video monitor and VHS tape recorder allowing a record to be made. She also had pictures explaining various common blood conditions. The process was simple, she pricked my finger with a clean needle, collected some blood on a slide, mixed in a clear liquid, and put it under the microscope. I've since been told that in a clinical setting, live blood cell analysis uses multiple samples taken from different parts of the body. In this case the woman took only one sample, from my finger.