Appendix

Formulations for flotation fluids and other reagents for use in diagnostic tests.

FLOTATION FLUIDS

The preparation of three different flotation fluids is described below. Any one of them can be used, depending on the availability of reagents. However, the salt/sugar solution (3) gives the best results due to its high specific gravity.

Good-quality inexpensive salt and/or sugar that gives a clear solution should be used for the preparation of flotation fluids. For convenience, a stock supply can be prepared (preferably in a clear container so the amount of salt/sugar not in solution can be seen). The solution should be stirred thoroughly before use to ensure that it is saturated.

(1) Saturated salt solution
Sodium chloride (kitchen salt)	400 g
Water	1000 ml
Specific gravity: 1.200
(2) Saturated sugar solution
Sugar	Q.S.
Water	1000 ml
Specific gravity: 1.120-1.200

Add sugar until saturation, indicated by the presence of sugar crystals at the bottom of the container after stirring for 15 minutes. Stir well before use.

(3) Salt/sugar solution
Sodium chloride (kitchen salt)	400 g
Water	1000 ml
Sugar	500 g
Specific gravity:	1.280

Dissolve the salt in water (saturated solution). Add the sugar to the saturated salt solution. Stir until the sugar is dissolved.

OTHER REAGENTS FOR USE IN DIAGNOSTIC TESTS

(1) Physiological saline solution (0.9%).
Sodium chloride (kitchen salt)	9 g
Distilled water	1000 ml

Dissolve the salt in water

(2) Aqueous iodine solution.
Iodine re-sublimed crystals	10 g
Potassium iodide	50 g
Water	1000 ml

Dissolve the potassium iodide in the water.

Then add and dissolve the iodine crystals.

(3) Formalin 3% solution.
Commercial formalin (40% formaldehyde)	3 parts
Water	97 parts

NOTE. The commercially available 40% formaldehyde solution is regarded as 100% formalin.

(4) Sodium thiosulphate.
Sodium thiosulphate crystals	124.1 g
Water	1000 ml

Dissolve the crystals in water.