(b) Egg slants.
Fresh eggs (medium-large) ............................... 4 ea
Locke's solution................................................. 50 ml
1 Emulsify the mixture in a large Erlenmeyer flask containing glass
beads or in a blender.
2 Filter through a double layer of gauze and dispense into 16 by
125 millimeter screw cap test tubes in seven to eight milliliter aliquots.
3 Place the tubes in slant racks and inspissate or autoclave (with all
exhaust valves closed) for 15 minutes at 15 pounds of pressure until the media gels.
NOTE:
The pressure must be allowed to escape from the autoclave at a very low rate.
A sudden drop of pressure causes bubbles and unsettles the media.
4 Allow slants to cool and overlay with two or three milliliters of
sterile Locke's solution under aseptic technique.
5 Incubate overnight at 35 C and check for sterility. Discard all
tubes that show a turbidity in the overlay layer of liquid.
6 Store in the refrigerator. Discard the unused media after a month
of storage.
b. Egg Yolk-Infusion: (Balamuth, 1946; modified). The liquid Egg Yolk-Infusion
medium has liver added and it is excellent for the cultivation of lumen protozoans. This
medium has the added advantage of slow deterioration when stored for up to two
months.
(1)
Reagents.
(a) Liver Extract Solution.
1 Dissolve 5.0 gm of Dry Extract of Liver (Wilson's) in 1000 ml of
distilled water and heat to boiling.
2 Filter through filter paper and sterilize at 121 for 15 minutes.
(b) Buffer solutions.
1 Stock solutions (1M).
MD0841
2-57