Hello,

I've never done it myself, but I happened to read this article. The team actually kept the parasites (Plasmodium) alive to be be able to easily differentiate them from the reticulocytes.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3614967/

I hope this will help :)

Thanks Rodrigues!

Using giemsa or wrights, you can try to differenciate young rings by morphology and mature forms by hemozoin. 

if you prepare thin film, you can easily apply wright stain and differentiate any parasite from the reticulocytes!