The coexistence of croton oil (CRO) increased the number of spins (NOS) from benzidine (BEN) in contact with deoxyribonucleic acid (DNA). NOS for a system arranged in the order of DNA-BEN-CRO for mixing was initially small and increased considerably to attain to a constant NOS. On the contrary, in the case of the DNA-CRO-BEN order, the large NOS was observed immediately after mixing, followed by slight increase of NOS. The time profile of NOS was also affected by the time interval between two mixing processes.