Vol. 10, Issue 2, Part B (2025)

Author(s): Srikanth Immadi, Subramaniam Kathiravan, Kanapadinchareveetil Sreelekha, Prashant Somalingappa Kurbet, Karapparambu Gopalan Ajithkumar, Anju Varghese, Chundayil Kalarikkal Deepa, Jess Vergis, Preethy John, Suresh Narayanan Nair, Reghu Ravindran and Sanis Juliet

Abstract: In the present study, ultramicrotome thin sections of the ovary of R. annulatus using glycol methacrylate-based resin were used for the interpretation of the cytotoxic effects of amitraz on the early stages of oocyte. Amitraz was applied at a concentration of 300 ppm. Fully engorged female ticks were divided into two groups: one exposed to methanol (control) and the other to amitraz for two minutes. After 48 hours, the ticks were dissected in phosphate-buffered saline. The dissected ovaries were fixed in 4% paraformaldehyde, dehydrated through an alcohol series, infiltrated with Technovit 8100, sectioned at 3µm using an ultramicrotome, and stained with haematoxylin and eosin. Histological examination of the resin embedded ultramicrotome 3µm sections revealed that the changes in the different stages of oocytes were clearer and more readable than paraffin embedded 5 µm ordinary microtome sections as reported in the earlier studies. The findings highlight the significance of the choosing the correct embedding material and fixative for the histological technique in studying the changes caused by the xenobiotics.