Comparative analysis of Rhipicephalus (Boophilus) microplus by scanning electron microscopy with and without gold coating.

Rhipicephalus (Boophilus) microplus is an obligate hematophagous ectoparasite that primarily infests cattle, transmitting diseases and causing economic, health, and productive problems in tropical and subtropical regions worldwide. Scanning Electron Microscopy (SEM) has become a tool with great potential for use in various studies involving this parasite. Although some studies affirm the importance of the sample coating process for good image quality, others report this same process hides the visualization of ultra-structures. This study aimed to compare images of R. (B.) microplus larvae using SEM with and without gold coating. Larvae aged 21 days after hatching were sampling this research. There were generated images by SEM and they were visually compared one another. Samples coated with gold for 20 s showed balanced contrast, but also exhibited artifacts due to metal agglomeration, which made it difficult to visualize details of the parasite's morphology. Those coated for 40 s showed cracking surface and structural disruption. Samples prepared without coating showed high contrast but rich fine details. In general, when deciding whether perform or not coating samples, the researcher should consider the study objectives, alternative conductors, and the availability of financial resources.