Magnetic Beads are commonly used to separate molecules or proteins using magnetic separation processes. Beads may be coated with different surface functionalities. Thiols provide a convenient functionalization for further chemical modification of beads, and carboxylic-acid terminated beads are readily available in various sizes. Here, we describe a protocol to conjugate thiols onto carboxylic acid-functionalized one micrometer magnetic beads. Cystamine was attached to the beads using via EDC (1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) and then disulfides were reduced with DTT (dithiothreitol). We performed various experiments to optimize the reaction and storage conditions for thiol functionalization and quantified free thiols with Ellman’s Assay. Reaction yield was optimal in low-pH buffer, and storage with the reducing agent beta-mercaptoethanol maintained free surface thiols.

Thiol conjugation to carboxyl-terminated magnetic beads

Macromolecular Chemistry: The Second Century

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ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.