*Fruitlessly pokes at the screen in an attempt to pop the bubbles* ^_^

Kidding...If you duplicated the geometry, and (uniformally) scaled it down slightly, you could have the "exterior" geometry have a semi-transparent, reflective and/or glossy surface that could act as glass, and the interior could be the "contents" of the tube; whatever goo or fluid is kept inside.

It's up to you; just throwing an idea out there