Fixatives
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Bouin’s Fluid
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| Ingredients | ||
| picric acid, saturated aqueous* |
75.0 ml
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| formalin |
25.0 ml
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| glacial acetic acid |
5.0 ml
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* Picric acid is sold saturated in water and must be stored that way, since in dry form it is explosive.
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Directions |
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For most specimens, fix 6-8 hours, or overnight. If specimen is smaller than 5 mm on a side, then several hours will suffice. Specimen may be stored in the fixative. Specimens should be fixed and stored in the refrigerator at 4ºC. |
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Carnoy’s fixative
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| Ingredients | ||
| glacial acetic acid |
100 ml
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| 100% ethanol |
300 ml
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Some Carnoy's recipes also include chloroform along with glacial acetic acid and absolute ethanol in the proportions 3:1:6. Chloroform increases the speed of fixation, making it useful for fixing tissues that are difficult to penetrate. Chloroform, however, is extremely hazardous and must be used in a ventilated hood while wearing gloves.
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Directions |
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For most specimens, fix 6-8 hours, or overnight. If specimen is smaller than 5 mm on a side, then several hours will suffice. Specimen may be stored in the fixative. This fixative severely hardens and shrinks the specimen, so the minimum fixation time should be used. Specimens should not be left in Carnoy's fixative for more than 2-3 days. Specimens should be fixed and stored in the refrigerator at 4ºC. |
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Dietrich’s FAA
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| Ingredients | ||
| 95% ethanol |
30.0 ml
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| formalin |
10.0 ml
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| glacial acetic acid |
2.0 ml
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| distilled water |
60.0 ml
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Directions |
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| For most specimens, fix 6-8 hours, or overnight. If specimen is smaller than 5 mm on a side, then several hours will suffice. Specimen may be stored in the fixative.
Specimens should be fixed and stored in the refrigerator at 4ºC. |
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