Vial Supports for Cleared and Stained Specimens

Cleared and stained specimens are commonly stained with alizarin red for bone and/or alcian blue stain for cartilage, bleached with a potassium hydroxide solution and cleared with the enzyme trypsin (Dingerkus and Uhler, 1977; Taylor and Van Dyke, 1985). Cleared and stained specimens are stored in 99% glycerine.

Because the specimens are usually small and fragile, it is preferable to house each individual in a separate container. Because glycerine is expensive, it is preferable to keep the specimens in small containers to reduce costs. However, specimen containers should not be so small that the specimen is damaged when removed for examination. Cleared and stained specimens should be kept in the dark when they are not being examined.

A few standard sizes of screw-cap vials should be used. Open ended cardboard tubes can be custom made to fit the diameters of the vials in use. The tubes are adhered together in a honeycomb pattern (See Ratcliffe and Messenger, “Vial Support System for Fluid Collections”, this volume) and fitted into boxes or drawers lined with polyethylene foam. Tubes for shorter vials are partially filled with polyethylene foam plugs to raise all vials to the same height.

• Copper tube, sharpened on one end
• Flint glass vials and screw-on caps
• Mitre saw
• Open-end cardboard tubes tube wall: 0.030 thickness
• Polyester pressure-sensitive tape, clear
• Polyethylene foam block for plugs
• Polyethylene foam sheeting
• Polyvinyl acetate emulsion adhesive
• Pressure-sensitive labels
  
  
  

1. Purchase cardboard tubes, custom-made or cut them to length with a mitre saw.
2. Fill a small standard cardboard drawer box with the tubes arranged in a honeycomb pattern.
3. Adhere the tubes together with polyvinyl acetate emulsion adhesive.
4. Line the bottom of the box or drawer with a layer of polyethylene foam to cushion the vial and reduce vibration.
5. After the adhesive in the honeycomb is dry, fit it into the box.
6. Label the top of the cap of each vial with specimen name and number. A more complete label may be attached to the outside of the vial by using press-on labels or attaching a small paper label with clear stable plastic tape.
7. For shorter vials, partially fill the tubes with polyethylene foam plugs, so that all vials are raised to the same height. Plugs can be cut out of polyethylene foam with a sharpened copper tube.
8. Insert the vials into the tubes.
   
   
   

Unless a very wide range of vial sizes is used, a tube diameter large enough to accommodate the largest vial will probably serve for the smallest too. The tube height should be sufficient to keep the vials upright but allow them to be grasped by the cap to be removed. A tube with an inside diameter of 1.15in leaves a 0.45in gap around a 6 dram vial. To insure adequate fit, send a sample vial to the manufacturer of the tubes.

Each vial should have an internal label with a unique identifying number because external labels might fall off and caps can easily be “switched” by careless researchers.