Posted Date
Effective Date
Update Type Test Methodology Changed



Ova and Parasites, Feces

Order Code:                  OAP

Fee Code:                     AA891, AA892

Reference Laboratory:   Mayo OAP


Effective January 5, 2023, there will be a change to the accepted Alternate Specimen types for Ova and Parasites, Feces, referred to Mayo Clinic Laboratories.  Mayo will no longer accept Low Viscosity (LV), mercury and copper (Cu) based PVA preservatives due to limitations observed in validation. 10% Buffered Formalin Stool Transport plus Zinc (Zn)-PVA will continue to be acceptable. The preferred preservative is ECOFIX.


Collection Instructions: Place specimen into ECOFIX preservative within 30 minutes of passage or collection. Follow instructions on the container as follows: a. Mix the contents of the tube with the spoon, twist the cap tightly closed, and shake vigorously until the contents are well mixed. Refer to the fill line on the ECOFIX vial for stool specimens. b. Do not fill above the line indicated on the container.


Alternate Specimen: Stool placed in 10% buffered formalin can be accepted if accompanied by Zinc (Zn) PVA-preserved specimen; 10% buffered formalin-preserved specimens submitted without an accompanying Zn PVA preserved specimen will be canceled. Specimen submitted in Low Viscosity (LV)-PVA, Mercury PVA or Copper (Cu)-PVA will be rejected. Duodenal aspirates, small bowel aspirates, or colonic washings should be placed in ECOFIX in a ratio of 1:1.