in analysing MDA content in plant tissues, I took 0.2 g leaf tissue (fresh welght), added 5 ml 0.1% TCA and samples were grind. samples then were centrifuged at 12500 rpm for 20 minutes. 3 ml from supernatant were put in a glass tube and 3 ml 20% TCA, 0.5% TBA was added, tubes were put in a water bath for 30 minutes at 90 C temperature.
and samples were read using spectrophotometer at 532 and 600 nm.
my question what is the correct formula to calculate MDA content in the samples?