The methods in the charts below are variations on the theme of picric acid to stain cytoplasm and muscle, and acid fuchsin to stain collagen. This simple formula has been modified for both dyes, so they have become characterized as incorporating a small molecular weight yellow dye in conjunction with a larger molecular weight red or blue dye at a distinctly acid pH. They differ from trichromes proper in that they never contain a polyacid, pH adjustment being done by the picric acid or some other acid. In spite of this, many histotechnologists consider these methods to be the simplest of the one step trichrome methods, since the basis on which they work is very similar.
Most of these variants can be used in a van Gieson type method, although the staining time may need to be changed, sometimes significantly. It may also be desirable to change the nuclear stain color to enhance contrast with the collagen, i.e. if a blue dye is used for collagen then a red nuclear stain may be appropriate.
Terms
- Dyes: To conserve space, dyes and chemicals are identified by abbreviations. These are explained at the end of this page. With most browsers an explanation will appear if the cursor hovers over each abbreviation.
- Amounts: Fluids are given in mL, and solids are given in grams. Sat. means a saturated aqueous solution.
- Picric acid: Since dry picric acid can be explosive it is suggested that it not be dried and weighed, but that an appropriate volume of the saturated aqueous solution be diluted with water to obtain the concentration required. At room temperature, 78 millilitres of a saturated aqueous solution of picric acid contains 1 gram of the solid.
- Acid fuchsin: For small amounts of acid fuchsin an appropriate volume of 1% acid fuchsin in distilled water may be added to the picric acid solution. One millilitre of such a solution contains 10 milligrams of the dye.
Picro-Fuchsin
| Variant | DW | PA | AF | Other | Comments |
|---|---|---|---|---|---|
| Fite | 100 | 0.5 | 0.1 | Sat. PA 40, DW 50, 1% AF 10 | |
| van Gieson | 100 | Sat. | 0.05 | ||
| Hansen | 98 | Sat. | 0.1 | AC 0.3 | |
| Lillie | 100 | 1 | 0.1 | HCl 0.25 | |
| Ohlmacher | 50 | Sat. 50 | 0.5 | Dilute sat. PA with DW | |
| Schaffer | 100 | Sat. | 0.15 | AC 0.05 | |
| Thompson | 100 | Sat. | 0.13 | ||
| Unna | 90 | Sat. | 0.25 | Gly 10 NA 0.5 | |
| Weigert | 100 | Sat. | 0.1 | ||
| Wilhelmini | 90 | AP 0.8 | 0.2 | Eth 95% 10 | AP explodes more easily than PA. Sat. = 1%. |
Picro-Dye
| Variant | DW | PA | Dye | Other | Comments |
|---|---|---|---|---|---|
| Curtis | 100 | 1 | PS 0.1 | AC 0.04 | |
| Gnanamuthu | Sat. 50 | CR 2 | AM 50 | Dissolve the CR in the PA. Add AM. Boil until there is no smell of AM. Cool. Add minimal DW to dissolve any precipitate. | |
| Herovici | 50 | Sat. 50 | AF 0.05 MB 0.025 | LC 0.05 Gly 10 | Dissolve AF in PA. Dissolve MB in DW. Combine. Add Gly and LC. |
| Puchtler | 100 | Sat. | SR 0.1 |
Abbreviations
| Abb | Meaning | Abb | Meaning | Abb | Meaning |
|---|---|---|---|---|---|
| AC AF AM AP CR | Acetic acid Acid fuchsin Ammonia Ammonium picrate Congo red | DW Eth Gly HCl LC | Distilled water Ethanol Glycerol Hydrochloric acid Lithium carbonate | MB NA PA PS SR | Methyl blue Nitric acid Picric acid Ponceau S Sirius red F3B |
References
- Gray, Peter. (1954)
The Microtomist’s Formulary and Guide
Originally published by:– The Blakiston Co.
Republished by:– Robert E. Krieger Publishing Co - Kiernan. J.A., (1999)
Histological and histochemical methods: Theory and practice, Ed. 3
Butterworth Heinemann, Oxford, UK.
