Preservatives, Stains and Reagents — Flashcards

Answer

A preservative is a chemical substance used to prevent decay, decomposition, or microbial growth in biological specimens. It helps maintain the structure and integrity of tissues for microscopic study…

Answer

Bouin's fluid is composed of: - Saturated aqueous picric acid – 70 ml - Formalin (40% formaldehyde) – 25 ml - Glacial acetic acid – 5 ml It is a rapid-penetrating fixative used for histological prepar…

Answer

Bouin's fluid penetrates tissues rapidly and provides excellent fixation of nuclear details without excessive hardening. It preserves fine cellular structures and is particularly effective for embryon…

Answer

Carnoy's fluid consists of: - Absolute alcohol – 60 ml - Chloroform – 30 ml - Glacial acetic acid – 10 ml It is prepared fresh due to its instability and is highly flammable and toxic. It gives excell…

Answer

FAA stands for Formalin-Acetic-Alcohol solution. Its composition is: - 50% alcohol – 100 ml - 40% formaldehyde – 6.5 ml - Glacial acetic acid – 2.5 ml It is an excellent general-purpose fixative that …

Answer

A stain is a chemical substance used to color specific cellular components or tissues to make them more visible under a microscope. Stains help differentiate structures like nuclei, cytoplasm, or cell…

Answer

Single staining involves using only one dye to color the entire tissue or cell. It highlights general morphology but does not differentiate between cellular components. Example: Acetocarmine stains bo…

Answer

Double staining uses two different dyes to selectively color distinct parts of a cell. For instance, Methyl green stains the nucleus green, while Pyronin stains the cytoplasm pink, allowing clear diff…