[The improvement of colorimetric determination of lipid peroxide in human serum].

The present work details an improved application of kit to the measurement of lipid peroxides in human serum. Kits based on the reaction of lipid hydroperoxides with a leucomethylene blue derivative in the presence of hemoglobin. Overall sensitivity was increased by taking samples 5 times larger than those indicated in product literature for the system. It was necessary, however, to compensate actual data for protein error. To do this, the following empirically obtained formula was employed: A = a/(-3.45x + 98) x 100, where A (nmol/ml) indicates compensated data for lipid peroxides, a (nmol/ml) indicates the data for the actual measurement of lipid peroxides, and x (g/dl) indicates the total protein. We obtained what we considered to be satisfactory results by the above formula, as it allowed us to observe that lipid peroxides in fresh human serum undergo a change, momentarily.