The Agarose superflow material is I think the same for Talon (Clontech) and Qiagen, not sure about Machery & Nagel or Sigma's product.
Superflow agarose is cross-linked differently than "normal" sepharose/cross-linked agarose. The nature of chelates and their attachments also differ. Qiagen, Sigma and Pharmacia use NTA while Clontech (Talon) uses carboxymethyl aspartate. Qiagen uses original chemistry through lysine spacer, Sigma's synthetic route is through bis-carboxymethyl cysteine (or -cystine), and Pharmacia opted for a clean but complex chemistry that results in a very hydrophilic spacer and higher degree of derivatization.
Dima
