Technology: Current cleanser keeps lenses clean

 作者:却翥按     |      日期:2019-02-28 01:02:01
A way to clean soft contact lenses without the detergents that can irritate eyes is being developed from a method used to transfer proteins in laboratory studies. Scientists at North Carolina State University say that the technique, called electro-blotting, cleans lenses thoroughly using just a trickle of electric current, blotting paper and saline solution. ‘This process may enable people who are allergic or sensitive to cleaning agents to wear contacts,’ says Harold Swaisgood, professor of food science and biochemistry at NCSU. Electro-blotting was developed to transfer proteins from a porous gel onto blotting paper. Protein molecules carry an electrical charge, either positive or negative, so in the presence of an electric field the molecule moves with a mobility proportional to the size of its charge. For cleaning lenses, which become coated with proteins from the wearer’s tears, electro-blotting causes proteins to migrate from the lens into wet blotting paper placed over both sides of the lens. ‘In just four hours, almost all the deposits on a lens have migrated onto the paper, which is then discarded,’ says Swaisgood. Marie Walsh, a member of the NCSU team, says: ‘Electro-blotting removed 94.42 per cent of the protein. Hand-washing with a commercial cleaner removed 86.87 per cent.’ For anyone allergic to the detergent, electro-blotting would be a useful alternative. Salem Products Development of Winston-Salem in North Carolina,