Vision lite 2.0 ml

The NH-EDx-, n-HDa-, n-ODa-, treated and control- fourth instars of A. aegypti and S. litura were fixed in Bouin’s solution overnight, flowingly dehydrated, and mounted in wax blocks using paraffin. Larval blocks of tissue were segmented using the microtome instrument (Leica, Germany), and the active sections were mounted on sterile microscopic glass slides, stained with eosin and hematoxylin, and observed for histopathological changes and photographed using light a microscope (Optika vision lite 2.0 ML) pre-connected with a laptop. Midgut cells of A. aegypti and S. litura were photographed, and the changes in the midgut cells of treated larvae were observed and matched with control [6 (link)].

The A. terreus ethyl acetate extract treated and control larvae (fourth instar) were fixed in paraformaldehyde solution (10%) for 1 week followed by embedded in paraffin. Larval tissue blocks were sectioned (7 μm) using the microtome (Leica, Germany), mounted on the glass slide and stained with haematoxylin and eosin for visualization purpose [under a bright-field microscope (Senthil-Nathan, 2007 (link))]. The sections were observed and photographed using a light microscope (Optika vision lite 2.0 ML) connected with computer. The midgut cells of the treated and untreated larvae of testing mosquitoes were photographed. The actual site of action in the midgut of treated larvae was observed and compared with control. As a control, the larvae were treated with tap water for 24 h.

The My-It-treated (1 × 10⁵ conidia/mL) and control larvae were fixed overnight in Bouin’s solution and then de-hydrated and fixed in blocks using paraffin wax. Microtome (Model: Leica, Germany) larval tissue blocks were fixed on sterile microscopic glass slides and stained using hematoxylin and eosin for examination under a bright field microscope and images were captured under an Optika vision lite microscope (2.0 ML). The captured midgut images of both My-It-treated and control larvae were further compared for toxicological screening.
The photomicrography assay was performed with the previous adapted protocol of Coelho et al. [27 (link)] with slight modifications. The My-It-treated and control fourth instar larvae were sequentially stabilized in an ethanol dehydration range from 35–70% for 25 min at 27 °C and fixed on microscopic glass slides. Finally, the sections were observed at 40× magnification under a light microscope (Optika vision lite 2.0 ML).