PROFICIENCY TESTING : Permanent Stained Smears

How should you examine a permanent stained fecal smear for proficiency testing?

Make sure the light is very bright (condenser all the way up) and the diaphragm is open. Review both thin and thick areas of the smear; examine at least 300 oil immersion fields (using the 100X oil immersion objective) before you report the specimen as a negative. If you use the 50X or 60X scanning oil immersion lens, you still need to review 300 oil fields as indicated above.