Stain can precipitate on the slide when it is not adequately rinsed. It can be mistaken for bacteria if not careful.

Bacteria on the slide can be a contaminant, especially if it is constricted to one area. The bacteria here also appears above everything else on the slide instead of being on the same level.

Water contamination can occur when the slide is not fully dry or in a humid environment. This can affect the appearance of RBC morphology, so these spots should be avoided or a new slide should be made.

It is important to differentiate between an RBC inclusion and an overlying platelet. Comparison with other nearby platelets allows for easy identification.

Artifactual teardrops are simply a consequence of slide-making and should not be reported. In contrast to true teardrops, these RBCs all have a sharp point facing in the same direction.