Keep your boule in a clean box when you are not taping it. These are the tubes you will attach to your SPM tip. Their lengths should be on the order of 10 s of microns. If you look closely you can see single multiwall nanotubes. There are two features that distinguish bundles from single tubes.
Single nanotubes are much dimmer, very straight, and very evenly illuminated.
You can also infer the position of single nanotubes you cannot see. Of course, none of these rules are absolute. In contact mode, they are not useful because the large lateral forced bend them too easily. We have not tried non-contact mode. We use TESP or FESP tips from Digital Instruments.