Immobilization of marine toxins on carboxylic acid modified surfaces

Saxitoxin and gonyautoxin 2 and 3 are among the most toxic components of the Paralytic Shellfish Poison from red tides. Being small molecules, they often require to be immobilized in order to be handled experimentally. Here is presented a methodology for covalently binding the toxins to carboxilatemodified surfaces. Both toxins were successfully bound to magnetic beads and saxitoxin was additionally bound to a modified golden surface in order to perform a surface plasmon resonance analysis. Success of binding to magnetic beads was evaluated through a standard immune-based toxin assay. Despite the different methods used for each toxin, the maximum binding yield for both toxins occurred when using concentration of 120 [micro]M. Keywords: PSP, ELISA, magnetic beads, plasmon, resonance, saxitoxin, gonyautoxin. Saxitoxina y gonyaulatoxina 2 y 3 estan entre los componentes mas toxicos del Veneno Paralizante de Mariscos de las mareas rojas. Al ser moleculas pequenas, a menudo requieren ser inmovilizadas para manipularlas experimentalmente. Se presenta una metodologia para la union covalente de las toxinas a superficies modificadas con carboxilatos. Ambas toxinas fueron exitosamente unidas a perlas magneticas y la saxitoxina fue unida ademas a una superficie de oro modificada para realizar un analisis de resonancia de plasmones de superficie. El exito de la union a perlas magneticas se evaluo mediante un inmunoensayo estandar contra las toxinas. A pesar que cada toxina requirio metodos diferentes, el rendimiento maximo de ligamiento para ambas ocurrio cuando se utilizaron concentraciones de 120 [micro]M. Palabras clave: VPM, ELISA, perlas magneticas, resonancia, plasmones, saxitoxina, gonyaulatoxina.