A fluid analysis apparatus comprising: a disposable card (14,100); an optical fluidic channel (172, 438) situated in the card (14,100); a first coupling region (160, 434) situated in the card (14,100); a fluid sample source (108, 431) connected to the first coupling region (160, 434); a lysing reagent source (64, 435) connected to the first coupling region (160, 434); a lysing channel connected to the first coupling region (160, 434); a sheath reagent source (68, 436); a second coupling region (170, 437) connected to the lysing channel and to the sheath reagent source (68, 436); the optical fluidic channel (172, 438) connected to the second coupling region (170, 437); and a light source (22a, 22b, 22c, 236, 346, 350) and detector (24a, 24b, 24c, 238, 239) proximate to the optical fluidic channel (172, 438), wherein light scatter measurements from the detector (24a, 24b, 24c, 238, 239) provide three part differentiation (lymphocytes, monocytes and neutrophils) of white blood cells characterized in that the apparatus further comprises a selective lysing reagent source (64, 435) connected to the first coupling region (160, 434), wherein the light scatter measurements provide a fourth part (eosinophil) differentiation of the white blood cells, the apparatus further comprising a second selective lysing reagent source (64, 435) connected to the first coupling region (160, 434), wherein the light scatter measurements provide a fifth part (basophil) differentiation of the white blood cells, and wherein light measurements from the detector (24a, 24b, 24c, 238, 239) are possible from all angles including ninety degrees. a disposable card (14,100); an optical fluidic channel (172, 438) situated in the card (14,100); a first coupling region (160, 434) situated in the card (14,100); a fluid sample source (108, 431) connected to the first coupling region (160, 434); a lysing reagent source (64, 435) connected to the first coupling region (160, 434); a lysing channel connected to the first coupling region (160, 434); a sheath reagent source (68, 436); a second coupling region (170, 437) connected to the lysing channel and to the sheath reagent source (68, 436); the optical fluidic channel (172, 438) connected to the second coupling region (170, 437); and a light source (22a, 22b, 22c, 236, 346, 350) and detector (24a, 24b, 24c, 238, 239) proximate to the optical fluidic channel (172, 438), wherein light scatter measurements from the detector (24a, 24b, 24c, 238, 239) provide three part differentiation (lymphocytes, monocytes and neutrophils) of white blood cells characterized in that the apparatus further comprises a selective lysing reagent source (64, 435) connected to the first coupling region (160, 434), wherein the light scatter measurements provide a fourth part (eosinophil) differentiation of the white blood cells, the apparatus further comprising a second selective lysing reagent source (64, 435) connected to the first coupling region (160, 434), wherein the light scatter measurements provide a fifth part (basophil) differentiation of the white blood cells, and wherein light measurements from the detector (24a, 24b, 24c, 238, 239) are possible from all angles including ninety degrees.