A simple method for preparing a diamino cellulose disk from a dialdehyde cellulose disk by reductive amination using 2-picoline-borane

A method for the preparation of dialdehyde cellulose disks (DACD) and subsequent diamino cellulose disks (DAmCD) was developed. DACD was prepared by oxidizing filter paper with sodium periodate. Subsequently, DAmCD were prepared by reductive amination of DACD with 2-picoline-borane. DACD enable the immobilization of amino group compounds and DAmCD enable the immobilization of aldehyde group compounds through Schiff's base formation. Bovine serum albumin and IgG were immobilized on DACD. Aldehyde-modified DNA was also immobilized on DAmCD. The target molecules were immobilized tightly by forming Schiff's bases. The amount of immobilization depended on the concentration of the target solution. However, it was possible to increase the immobilized amount by repeating the drop-and-dry even if the concentration of the target solution was low. This is because Schiff's base is formed by the removal of water. Since filter paper is easy to obtain and handle, this method is simple and low-cost and can be applied to many experiments.