The system has two major principles of measurement, one is colorimetric and the other is potentiometric. Colorimetric slides based on measurement of the reflection density of the slide can be classified into two categories. One is endpoint slides which measure general chemistry parameters such as glucose (GLU), blood urea nitrogen (BUN), uric acid (UA), creatinine (CRE), total bilirubin (TBIL), total protein (TP), calcium (Ca), tri-glyceride (TG) total cholesterol (TCHO) etc., and the other is rate slides which measure enzyme parameters such as - glutamyltransferase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phophatase (ALP), lactate dehydrogenase (LDH), creatinine phosphokinase (CPK), amylase (AMYL) etc. In case of the endpoint slides, reflection density at the fixed time point after spotting the sample, is measured and converted into the concentration of the analyte by a calibration curve. In case of the rate slides, changes of reflection destiny between two time points are measured and converted to the activity of the analyte by a certain formula. The actual measurement is done as follows in case of the glucose slide. 10 microliter of plasma or serum is spotted on a FUJI DRI-CHEM SLIDE GLU-PIII. After spotting, the sample spreads uniformly on the spreading layer and diffuses into the underlying layer. As the process proceeds, large molecular weight components such as proteins or dye components are filtrated, and only small molecular weight components are able to permeate and diffuse into the reagent layer. Glucoseoxidase (GOD) catalyzes the oxidization of sample glucose to generate hydrogen peroxide. In the presence of peroxidase (POD), hydrogen peroxide reacts with dye precursors and finally forms red dye. The slide is incubated at 37°C for certain minutes in the FUJI DRI-CHEM analyzer and the optical reflection density is measured at 505nm. The aforementioned optical reflection density is then converted into the glucose concentration using a calibration curve preinstalled in the analyzer. Potentiometric slide is based on measurement of the generated voltage difference between ion selective electrodes applied with reference solution and the sample. In FUJI DRI-CHEM system, ion selective electrodes for sodium (Na), potassium (K) and chloride (Cl) are set into one slide. After spotting 50 microliter of the sample and of the reference solution on the slide, the slide is incubated for one minute in the FUJI DRI-CHEM analyzer and the potentiometric difference between the sample and the reference solution is measured. The potentiometric value is then converted into each of the electrolyte’s concentration using a calibration curve preinstalled in the analyzer. Back