Addis1,2 established the fact 30 years ago, with use of a counting chamber, that both white and red cells normally occur in urine. He found top values of 2,000,000 white cells and 400,000 red cells in the 12-hour night urine specimens of 74 apparently healthy medical students. Inasmuch as the collections averaged 352 ml., it appears that some 6,000 white cells and about 1,000 red cells may be expected per milliliter of urine in health. However, Addis' method has been found too cumbersome for general use, and his results for whole urine have seemed of limited value, since they were not correlated with simultaneous counts per hpf of the centrifuged sediment, the more familiar procedure.*
I have made a series of 500 such correlations between cell counts of the sediment prepared in the usual fashion and simultaneous cell counts of the whole urine by use of the counting chamber.
WRIGHT WT. Cell Counts in Urine. AMA Arch Intern Med. 1959;103(1):76–78. doi:10.1001/archinte.1959.00270010082010