not sure why this is in the immune system category but Igepal is the tradename for a series of poly(oxyethylene) alkyl ethers. Commonly used as a non-ionic surfactant, especially in micelle synthesis.
Tide, Wisk, Simply Clean, Joy, Ivory Liquid, Igepal 630, and Zyfo all carry nonionic soaps. Check the label to confirm that the soap you are purchasing is nonionic.
It dissolves the cell mebrane. Keep in mind that some people do not use Triton X-100 in cell lysis, but instead sonificate... Also Triton X-100 can be replaced by a whole lot of other stuff (CHAPS, Igepal, etc) Hope to have givin you enough info