Carnoy fluid

Carnoy fluid consisting of 6 parts absolute alcohol, 3 parts formaldehyde and i part of glacial acetic acid, can also be used for fixing small objects. It has the advantage of fixing these in about 10 minutes. Moreover the objects can be carried directly to absolute alcohol, thence to Paraffin and imbedded. 

Host embryos can be fixed from several hours after the operation to several days after hatching according to the experimental design (see Note 20). Carnoy fluid is one of the best fixatives utilizable at once for Feulgen and Rossenbeck staining (13), immunohistochemistry, and in situ hybridization on paraffin sections. Fixation with 4% paraformadehyde is used for whole-mount immunohistochemistry and in situ hybridization, and all treatments on cryostat sections. 

Methacarn is a fixative used on tissues to be paraffin-embedded and immunochemically stained in which methanol has been substituted for the ethanol in Carnoy s fluid. This methanol-Carnoy mixture is referred to as methacarn solution. It preserves certain tissue and cell components such as collagen and cytoskeletal elements exceptionally well for immunoperoxidase and other immunochemical staining (8). 

Fig.84. Bronchiolar Clara cells of a male mouse (M 91/61) which was medicated with intraperitoneal injections of 100 mg isoniazide (Neoteben) per kg body weight every week and was sacrificed under methitural anaesthesia after 41 days of experimentation. Fixed in Carnoy s fluid (ethanol -chloroform - glacial acetic acid). Paraffin embedding. Trichrome stain after Goldner. Eyepiece Leitz Periplan 4x objective Leitz PI Oil 100/132...

Fig. 135. Alveolar macrophages having engulfed powdered diamond. 3-Day old culture of a 3-day old mouse. The preparation was fixed in Carnoy s fluid, stained with iron hematoxylum after Weigert, and mounted in toto in Rhenohistol. Eye-piece Leitz Peri-plan 4x objective Leitz Pv FI oil 70/1.15. Positive phase contrast (from Schiller 1954)...

Radioautography at the cellular level was applied to the study of brain lipids after injection of various precursors, such as acetate, labeled either with H or with in position 1 or 2, serine-3- C or cholesterol- H (Torvik and Sidman, 1965). Since some of these precursors were incorporated into proteins, lipid activity was determined by subtracting the radioautographic reaction observed over sections derived from tissue fixed in Carnoy s fluid (which will extract most lipids) from that seen over formalin-flxed frozen sections. The authors attempted to localize more closely the site of lipid formation in the brain and concluded that the rate of uptake was most... 

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