Since the published formulation you have doesn't specify, I think its fair to assume you can use any store-bought detergent, and it would work fine. As I understand it, DawnTM Brand kitchen detergent is favored among other brands for soap bubble experiments and washing birds and mammals exposed to spilled crude oil, so there's a vote. If you want, you can order Sodium dodecyl sulfate in very pure form for molecular biology research, if you want to be sure you avoid interference. Unless you want something non-ionic to avoid all possible interference, like Triton X-100 or nonoxynol-9, likewise available very pure. See if you can find a reference to those particular detergents with this reagent preparation.