Hello everyone,

I am working on a project involving the incubation of plasmid DNA with cisplatin, which should result in a change in electrophoretic mobility of the DNA, making the OC form migrate faster and the CCC form slower. The paper I am following says that they quenched the reaction by adding 4mL xylene (yes, mL, not uL). It seems as though the xylene is meant to remove all the unbound cisplatin from the reaction solution, so that the reaction does not continue during electrophoresis (just my guess). However, literature tells me that cisplatin is insoluble in most organic solvents, except DMF, DMA and DMSO. How is the xylene quenching this reaction? Is it crucial for accurate results? It's rather difficult to remove the reaction solution out of the xylene without removing some xylene along with it, which makes it impossible to load samples evenly. Does anyone have any thoughts on this?

Thanks in advance!

(Citation: Photoswitching the Cytotoxic Properties of Platinum(II) Compounds. Angew. Chem. Int. Ed., 54: 4561–4565. doi: 10.1002/anie.201412157)

PS: I'm thinking now that the xylene does not quench the cisplatin-DNA reaction, but rather the platinum compound-DNA reactions. They are comparing the DNA binding properties of platinum compounds they synthesized to the cisplatin (since it is commonly used in chemotherapy). Does this sound plausible?