Loading beads into numerous microvials or deep

	BioSpec Products, Inc. (800) 617-3363 or (918) 336-3363

Loading beads into numerous microvials or deep-well microplates can be tedious. Here some solutions - some you can fabricate yourself............

Loading Microvials: If you have a vacuum line in the lab, make a "bead sucker upper". Obtain a 1 ml plastic syringe (also called a tuberculin syringe). Discard the syringe plunger and cut the barrel with a scalpel to a length that will contain one ml (or some other lesser volume) of beads. Push a small stainless steel mesh disc all the way down the barrel using a nail, a drill bit or some thick wire. Call us and we will provide you with the mesh disc - no charge. Hook up the needle-end of the syringe to some thick walled tubing and the other end of the tubing to the vacuum line. Dip the modified syringe barrel into a container of beads, transfer the loaded beads under vacuum to the receiving vial and "break" the vacuum. The beads fall out into your receiving vial.

Practical variations include using thick-walled tubing having a large hole drilled into its side. Draw up the beads while your finger covers the hole and unload the beads by sliding you finger off the hole. Another variation involves using a "compressed air blow gun" available at hardware stores. Connect to a vacuum line via some thick-walled tubing, squeeze the air gun valve to draw up the beads, and open the air gun valve to unload the beads into your vial. The later device requires a small nylon piece having a female Leur fitting on one end and a threaded region on the other end. The piece allows connection of the "bead sucker upper" to the air gun nozzle. Our prototype loader required an adapter with 10-32 UNF threads and the end of the air gun nozzle was drilled and tapped for that thread size. One source of these adapters is the Cole-Parmer Instrument Co. catalog under "Luer, plastic".

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And here's another idea - from one of our users, Ron Moore: Ron's loader is very easy to construct but more "skill intensive" to use than the device described above. He uses a Keck Clamp (a.k.a. Thumb-clamp) to regulate the gravity flow of 0.1 or 0.5 mm diameter beads from a bead bottle or large funnel, through about one foot of thin walled, 3/8 inch OD, rubber or PVC tubing and, finally, into the vial. Bead flow through the tubing is regulated with the Keck Clamp. You may have seen this type clamp on hospital IV infusion sets - but those clamps are too small for the present application. Cole Parmer Instruments sells one that is large enough, Cat No C-06835-07, at about $5 each.

Loading Deep-well Microplates: See our web page on the MiniBeadbeater-96 for a couple of bead loaders designed to load 1 ml of beads into 2 ml capacity 96 deep-well microplates. It is possible to deliver smaller than a 1 ml volume of beads per well but it requires modification of our presently available loaders. Call us.

Some tough plant samples are best homogenized in deep-well microplates using one or two 6.35 mm diameter beads made of glass or steel. A microplate loader for these large beads can be made using a standard capacity 96 well polystyrene plate. Each well of this plate holds exactly two beads per well. Transfer the beads by place the receiving deep-well microplate over the bead-filled standard microplate and invert the pair. If you want to limit the load to one bead, decrease the capacity of the standard microplate by gluing a single bead to the bottom of each well using model airplane cement (this glue comes in a squeeze tube. It adheres well to polystyrene plastic).