The body produce oxygen free radicals through the enzyme system and non-enzyme system, which can attack unsaturated fatty acid on biofilm and lead to lipid peroxidation and form lipid peroxide, such as aldehyde group (MDA), keto-, hydroxyl, carbonyl, etc. Oxygen free radicals cause cell damage not only by peroxidation of polyunsaturated fatty acids in biofilm, but also by decomposition products of lipid hydroperoxide. Detection of the MDA content can reflect the level of lipid peroxidation in cells and reflect level of cellular damage indirectly.

MDA in the catabolite of lipid peroxide can react with thiobarbituric acid (TBA) and produce red compound, which has a maximum absorption peak at 532 nm.

1.  It is recommended to fasten the glass tube mouth with preservative film and make a small hole in the film.

2.  Water-bath temperature (95-100℃) and incubation time (40 min) should be stabilized. Cool the tubes with running water immediately once the incubation finished.

3.  The supernatant for assay should not contain sediment, otherwise it will affect the OD values. It is recommended to use a pipette to take the supernatant.

4.  The sampling quantity of blank tube, standard tube and sample tube can be increased to 100 μL if the MDA content of samples is low.

5.  Accurately take 250 μL reaction solution into the 96-wells and without bubble.

                                               [Note]: A-H, standard wells; S1-S80, sample wells.