DNA Cleavage Assay of Novel Compounds

DNA supercoiling plays a key role in gene expression and genome organization [79 (link)]. The agarose gel electrophoresis assay was used to check whether the tested complexes 3a–3c are able to cleave DNA. Supercoiled plasmid pUC57 DNA (4634 bp); Thermo Scientific, ABO Sp. z o.o., Gdansk, Poland), was incubated with tested compounds (100, 200 and 300 µM). Next, loading buffer (1 μL) containing 25% bromophenol blue, 0.25% xylene cyanol and 30% glycerol was added to allow the samples to be loaded into 1% w/v agarose gel. Electrophoresis was performed at 75 V in Tris-acetate- EDTA (TAE) buffer. The gel was stained using Midori green advance DNA stain (Genetics, ABO Sp. z o.o., Gdansk, Poland), and visualised under UV light with the BioRad Gel Doc 2000 system using LABWORK software (Hercules, California, USA). All experiments were carried out in triplicate under the same conditions.