Ova and Parasite (O&P) Examinations

Microscopic Examination - Ova and Parasite Examination

Place 1 drop of 0.85% NaCl on the left side of the slide and 1 drop of iodine (working solution) on the right side of the slide. If preferred, two slides can be used instead of one.
Take a small amount of fecal specimen (the amount picked up on the end of an applicator stick when introduced into the specimen) and thoroughly emulsify the stool in the saline and iodine preparations (use separate sticks for each).
Place a 22-mm coverslip (no. 1) on each suspension.
Systematically scan both suspensions with the 10 x objective. The entire coverslip area should be examined under low power (total magnification of x 100).
If something suspicious is seen, the 40 x objective can be used for more detailed study. At least one-third to one-half of the coverslip should be examined under high dry power (total magnification of x 400) even if nothing suspicious has been seen.
Another approach is to prepare and examine the saline mount and then add iodine at the side of the coverslip. The iodine will diffuse into the stool-saline mixture, providing some stain for a second examination. Remember, the iodine will kill any organisms present; thus, no motility will be seen after the iodine is added to the preparation.