A researcher into cancer was explaining to me his intracellular experiments with microtubules which are around 2 microns in diameter. He wants to test the electrical current across the length of a microtubule but needs to insert an electrode positionable within +/- 5nm !! Do you know if anything like this exists?? Can you help him out?? Rob Santilli APPLIED MICROENGINEERING LTD 68 MILTON PARK ABINGDON, OXON, OX14 4RX, UK TEL: +44 (0)1235 833 934 FAX: +44 (O)1235 833 935 WWW: http://www.aml.co.uk