Egg Albumen Adhesives
Egg albumen adhesives are in common use and all of the variants work well. Although each specifies a different preservative to inhibit bacterial and mold growth, many technologists find that a small crystal of thymol satisfactorily replaces sodium salicylate, Sodium p-hydroxybenzoate or merthiolate and is much simpler to use.
|Separate the whites from the yolks of fresh chicken eggs. Discard the yolks. Beat the egg whites until they are homogenous but still fluid. Add the glycerol to the egg whites and mix well. Add the sodium salicylate and mix well to dissolve. Filter through a few layers of gauze to remove any membranes etc.|
Fresh egg whites
|Dissolve the sodium p-hydroxybenzoate in the normal saline. Separate the whites from the yolks of fresh chicken eggs. Discard the yolks. Beat the egg whites until they are homogenous but still fluid. Add an equal volume of the saline to the egg whites and mix well. Centrifuge the mixture until it is clear, and decant the supernatent for use.|
Dried egg albumen
Merthiolate, 0.1% aqu.
|Combine the water, egg albumen and sodium chloride, then gently mix to dissolve. Filter, then add an equal volume of glycerol to the filtrate and mix until even. Add the merthiolate and mix until even|
Keep a small quantity in a capped container for use. Blood bank antisera bottles are suitable. Refrigerate the stock. Discard the stock if it smells or becomes turbid. This may take some time, even several months or longer.
To use, smear a tiny amount evenly over a clean, grease free slide. Pick up the section from a tissue flotation bath and bake on as usual. The most common problem encountered is from applying too much. Only the tiniest amount should be dotted onto the slide, then spread over the relevant part of the slide with the finger tip and finally wiped with the edge of the hand to remove as much as possible.
Alternatively, the stock may be diluted 1:20 to 1:50 with water and a few drops placed onto a slide. The section may be floated on this and gently warmed to expand and remove wrinkles. The slide is then drained and baked on as usual.
A useful variant is to burn the albumen smeared on a slide to increase its adhesion. Spread the egg albumen on the slide as usual, then hold it in a flame for a few seconds until it smokes. Be careful not to heat the glass slide too much as only a little heat is needed. Allow to cool, then pick up the section from a tissue flotation bath and bake on as usual. These slides are better prepared ahead of time and used when needed.
Regardless of how the adhesive is used, if the albumen can be seen after staining, then too much has been applied.
Gray, Peter. (1954)
The Microtomist's Formulary and Guide.
Originally published by:– The Blakiston Co.
Republished by:– Robert E. Krieger Publishing Co.
Journal of the Royal Microscopical Society, v. 4, p. 317.
Stain Technology v. 20, p. 99
Geneva, New York, USA.
Steedman, H.F., (1960)
Section cutting in microscopy
Blackwell Scientific Publications, Oxford, UK.