This is a very old method for supravital staining, that is staining of
fresh, living, unfixed blood cells in wet films under coverslips.  It was
first described in the late 40's or early 50's, in an article in STain
Technology (I think).  I used this method in a project in about 1962, and
found it to be somewhat useful, but very difficult to achieve consistent
results.  Sorry I don't have specific references, but it has been a long
time!

Al Floyd
23126 South Shore Drive
Edwardsburg, MI 49112
(616) 699-7182 phone & fax