Uv vis spectrophotometer model uv 1280

Using an Eppendorf pipette, 2.5 ml of standard tannic acid solutions at concentrations of 0.25, 0.50, 0.75, 1, 2, 4, and 8 mg/ml were measured and placed separately in labeled glass test tubes. In each of the test tubes, 2.5 ml of hemolysate from a pooled blood sample was added and mixed and then allowed to stand for 15 minutes. The preparation was centrifuged at 7000 rpm for 5 minutes on a Hettich machine (Andreas Hettich GmbH and Co. KG, Germany). The supernatant was transferred into clean, labeled test tubes using a Pasteur pipette, and the optical density (OD) was read at 578 nm using a Shimadzu UV-Vis spectrophotometer model UV-1280 (Shimadzu, Japan). The OD obtained at various concentrations of tannic acid was plotted on a standard curve, and then a line of best fit was determined.

A volume of 2.5 ml of blood hemolysate was placed into a clean, labeled glass test tube. An equal volume of the respective extract (or control) solution is added into the test tube containing the blood hemolysate. The hemolysate extract (or control) mixtures were allowed to stand for 15 minutes at room temperature before centrifugation using a Hettich machine (Andreas Hettich GmbH and Co. KG, Germany) at 7000 rpm for 5 minutes. The supernatant from each preparation was separated into clean, labeled test tubes, and their absorbance was measured at 578 nm using a Shimadzu UV-VIS spectrophotometer model UV-1280. The test was done thrice for each blood sample. The average absorbance was calculated, and the results were recorded.