PVA fixative-preserved specimens

Preserve 1 part specimen in 3 parts PVA fixative. Mix thoroughly. Fix for at least I h. Specimens keep indefinitely. 

Spread the material over the center third of the slide by rolling the specimen with an applicator stick. Remove any lumps. The film should extend to both the top and bottom edges of the slide, as this helps prevent peeling. 

Allow the slide to dry overnight at room temperature or 35 °C. In an urgent situation, the slide can be dried for 4 h at 35 °C and then stained. 

Permanently stained slides may be mounted with a cover slip or may be air dried and examined after oil is added. Slides should be examined at a magnification of x400 to X500 or greater after they are scanned under lower power to find optimal areas. A x50 oil immersion objective is particularly helpful, as it allows the easy use 

Permanently stained slides should be kept for 2 years. 

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