Possible insertion of double-stranded DNA (ds-DNA) alternating copolymers into the inner space of a multi-walled carbon nanotube (MWNT) with a sufficiently large diameter is experimentally examined and characterized with STM/STS and TEM techniques. The STM images clearly reveal the DNA-encapsulation process through an open-end of a tube and also the DNA-wrapping on the outside-surface of a tube. The spatially resolved STS analysis also supports the encapsulation of ds-DNA in MWNT. (c) 2005 Elsevier B.V. All rights reserved.