HAMES Laboratory Method for Wet-mount microscopy:
Preparation of 0.9% saline solution

Purpose

Gill or skin tissues sampled from tilapia for wet-mount microscopic examination is a useful procedure for recognition of ectoparasite infections. Once tissue scrapings are collected these should be gently placed into a drop of clear solution for viewing under the microscope. Experience has shown that the immersion solution should be isotonic or nearly isotonic with the tissues so that unnecessary uptake of water and the resulting tissue swelling are minimized. A simple salt (NaCl) solution works well for this purpose.

Preparation

1. To make 100 mls of saline solution: Add 0.9 grams of NaCl to 100 mls of clean tap water in a clean glass container.
2. To make 1 liter of saline solution: Add 9 grams of NaCl to 1 liter of clean tap water in a clean glass container.

Label the container; the solution can be store indefinitely if the container is sealed.