TNBS Assay

TNBS Assay
Protocol 1

1. Mix 0.4 ml of DNA-polymer complex (made 20 ug/ml DNA concentration) with 0.4 ml
0.1 M Na2B4O7.10H2O. Add 0.02 ml TNBS solution diluted from 1 M stock solution
to 15 mg/ml with water
2. Incubate for 45 min at room temperature and measure absorbance at 420 nm
(absorbance of the solution made from PLL (20,000)-DNA N:P=2 is usually about 0.35.
3. As a blank, add 0.02 ml TNBS to 0.8 ml borate buffer

Protocol 2
1. Add 20 ÎŒL of sample (in duplicate) to 130 ÎŒL of 0.1 M phosphate buffer (pH = 7.0).
2. Add 850 ÎŒL of 1 mM TNBS in borate buffer (pH = 9.0).
3. incubate at 37 °C for 1 h.
4. Measure OD367.