Abstract: A wheel assembly comprises a generally frustoconical wheel having an upper wall defining a recessed area and a lateral wall with a tapered outer surface; a generally frustoconical rim having a top wall defining a central hole and a side wall with an outer surface and a tapered inner surface complementary with the outer surface of the wheel; and a solid tire attached to the outer surface of the rim. The recessed area is partially covered by the top wall of the rim when the rim is installed on the wheel. To install, the rim is slid over the wheel, and the rim and tire are bolted to the wheel. To remove, the bolts are removed, a pry bar is inserted in the recessed area of the wheel, and the rim is pried away from the wheel.

Abstract: A cyanine dye having the structure has an overall positive charge greater than +1, by virtue of the presence of one to five positively charged N or P or S atoms, and also has a reactive or functional group by which it may be linked to a biomolecule or a solid surface.