Fibers are urinary artifacts and should be differentiated from casts. They are typically flat with dark, well-defined edges. Under polarized light, they are typically highly refractile.

Spermatozoa have a small, bulbous head with a long, thin tail that may detach.

Starch granules are round with irregular indentation in the center. Under polarized light, they form “Maltese crosses.”

Fat droplets are highly refractile and form a “Maltese Cross” pattern when polarized.