A different way to make the "spin columns" described by Dr. Roychowdhury
is to place the gel slice on top of the aerosol-barrier of a cheap barrier
tip. The more expensive barrier tips have a hydrophobic locking material
in the filter, making them useless for this application.
The tip and gel are then frozen, placed in a microtube and centrifuged as
(even cheaper than Hiryana!)