What is the preservative used for stool samples for ova and parasite examination?

The preservative utilized for stool samples intended for ova and parasite examinations is sodium acetate-acetic acid-formaldehyde (SAF). This specific preservative offers several advantages critical for maintaining the integrity of the sample. It effectively preserves the morphology of parasites, ensuring their structures remain intact for subsequent microscopic evaluation. Additionally, it prevents the breakdown of the sample, which can occur due to bacterial overgrowth or decay.

Formaldehyde, while a common preservative, is not as suitable alone for stool specimens because it can alter the morphology of certain parasites. Isopropanol and ethyl alcohol are not recommended for this type of specimen retention, as they may cause dehydration of the samples and can lead to the loss of essential visual details needed for identifying parasites.

Given the context of preserving stool samples for thorough examination of potential parasitic infection, sodium acetate-acetic acid-formaldehyde is the optimal choice due to its balancing act of stabilization and clarity of sample morphology.