Improvement of the observational method for Plasmodium berghei oocysts in the midgut of mosquitoes

摘要

BackgroundThere is a need for improving the method for counting oocysts of Plasmodium berghei in the midgut of Anopheles mosquitoes. The two methods currently used, the formalin fixation method and the mercurochrome staining method, have contradicting advantages and disadvantages. In the formalin fixation method, the specimen can be preserved but unstained oocysts were often indistinct from the insect tissue. While in the mercurochrome staining method, stained oocysts can be clearly distinguished from insect tissue but the specimen are not well preserved. These two methods were combined in this study to develop a new improved technique in counting the oocysts, in which the specimen can be both stained and preserved well. This technique was evaluated for its accuracy and suitability in observing the oocyst development.