Erythrocyte bitemporal examination, a phase contrast microscopy, is used to identify the source of red blood cells in the urine. This test can distinguish between hematuria due to glomerulonephritis or hematuria due to bleeding from other sites. If the aberrant red blood cells are greater than 85% on the red blood cell phase examination, or if spindly red blood cells greater than 5% are present, hematuria of glomerular origin is considered, i.e., glomerulonephritis is considered. If normal red blood cells are greater than 85%, consider red blood cells of non-glomerular origin, possibly hematuria due to urinary tract infection, urinary stones, urinary tract tumors or bleeding from other sites. This test needs to be done with morning urine and preferably 3 times in a row for greater significance.