Lugol’s Iodine, Stain Concentration. Useful in identifying difficult to see parasites on fecal floatation or wet mounts. These include protozoan parasites like Giardia, Coccidia, and also helminth parasites. This stain is picked up readily by protozoan nuclear structures and also stains their glycogen masses. Some parasites, like Giardia are very difficult to view unless stained in this manner. 500ml with 4 oz. dropper bottle. 2.1% Iodine Stain. 500ml.