Sectioning insects with sclerotized cuticle.
TL;DR: Adult insects of different orders including beetles were fixed in a mixture of a saturated solution of picric acid in 90% alcohol, 75 parts; formalin, 25 parts; nitric acid (cone), 8 parts, 4–6 days and even up to 10 days depending upon the hardness of the cuticle.
Abstract: Adult insects of different orders including beetles were fixed in a mixture of a saturated solution of picric acid in 90% alcohol, 75 parts; formalin, 25 parts; nitric acid (cone), 8 parts, 4–6 days and even up to 10 days depending upon the hardness of the cuticle (addition of 5% mercuric chloride to this mixture is recommended when prolonged immersion is required), or in Carnoy and Lebruns' fluid 24–48 hours and then transferred to a solution of 3–6 parts of nitric acid in 100 parts of 90% alcohol (3–6 days). After dehydration in different grades of alcohol, the insects were double embedded in celloidin and paraffin, either by (1) clove oil for 1 day, then to a saturated solution of celloidin in clove oil matured for at least 2 months for 20–40 days, or (2) the conventional ether-alcohol-celloidin mixture for 7 days; followed by hardening in chloroform. The difficulty in the proper infiltration of paraffin into celloidin hardened by chloroform around the insect is avoided by keeping the block overnight i...
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TL;DR: This technique can produce serial sections as thin as 5 μ from hard chitin-covered materials of insects or other arthropods by subjecting material to partial vacuum in each step to ensure a final proper embedding.
Abstract: This technique can produce serial sections as thin as 5 μ from hard chitin-covered materials of insects or other arthropods. Procedures: Fix with alcoholic Bouin's fluid for 3 hr. Henceforth subject material to partial vacuum in each step to ensure a final proper embedding. Wash with 80% ethanol 2 or 3 times for 2 hr or until the picric acid is largely removed. Dehydrate to 90% ethanol and give 2 changes of n-butanol 2 hr each, and one of a 1:1 n-butanol-paraffin mixture in 56-57° oven for 12 hr. Finally, use 2 baths of pure paraffin, 3 hr each, to complete the infiltration. After the last bath, withdraw the specimen from the paraffin, and remove the superficial paraffin, first mechanically and then with a xylene bath for 4 min. Rinse first with n-butanol, and afterwards with absolute ethanol, 2 min each. The compound eyes are protected with a paraffin covering, the specimen is hydrated with a 1% aqueous solution of detergent for 1 hr and then washed with running tap water. The material is treated with a ...
5 citations
TL;DR: With few exceptions, de-stained sections can be re-stained with mucihematoxylin, PAS or Gabe's trichrome and this requires prior de-staining.
Abstract: Re-staining of formalin fixed paraffin sections sometimes is required and this requires prior de-staining. Some simple and effective protocols for de-staining are described. Mucihematoxylin and mucicarmine can be removed with acid alcohol. Zirconyl hematoxylin can be removed with periodic acid or Sinha's fixative. Alcian blue can be removed with 5% trifluoroacetic acid in dichloromethane. Colloidal iron can be bleached in 1% household bleach in alcohol. PAS can be removed with hydrogen peroxide or ammonium hydroxide. With few exceptions, de-stained sections can be re-stained with mucihematoxylin, PAS or Gabe's trichrome.
3 citations
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TL;DR: The reproductive organs of Bruchus quadrimaculatus Fabr.
Abstract: The reproductive organs of Bruchus quadrimaculatus Fabr., and B. (Callosobruchus) chinensis L., including histology are described in detail. The role of the different parts of the male and female copulatory apparatus is discussed and the physical composition and function of the secretions of the accessory glands are indicated. The specific differences in the structure of the genitalia of the two species are shown.
15 citations