Abstract

Objectives: Sodium hypochlorite (NaOCl) is widely recognized for its unique ability to dissolve tissues, making it a common choice for the exsheathment of nematode larvae in various studies. This chemical has frequently been utilized for larval exsheathing at different concentrations, with exposure durations varying significantly across studies. However, concerns have been raised regarding the impact of this compound on the viability of exsheathed larvae. The current study aimed to identify the optimal chemical concentration and the shortest exposure time that can be used without compromising larval viability, using third-stage strongylid larvae cultured from donkey fecal material as a model. Methods: Larvae were treated with NaOCl concentrations of 0.025%, 0.05%, 0.1%, 0.2%, 0.3%, or 3% and observed for 3-, 5-, or 10 minutes post-treatment. Visual immobility and noticeable morphological changes were used as criteria for assessing viability. Results: The results indicate that a concentration of 0.025% is optimal, as it does not adversely affect larval viability even after 10 minutes of exposure. In contrast, a significant reduction in the proportion of motile larvae was observed when the concentration was increased to 0.05%, with 6.02% of the 415 larvae analyzed exhibiting sluggishness. Higher concentrations were associated with decreased motility or immobilization of the larvae. At the extreme concentration of 3%, the larvae exhibited significant damage. Conclusions: Given the widespread use of NaOCl as an artificial exsheathing agent for nematode larvae and the variety of protocols employed, the current findings provide a valuable reference for researchers utilizing NaOCl in nematode studies.