Cryopreservation of jaguar (

Somatic cells serve as essential genetic resources for biobanking. Traditionally, jaguar fibroblast-like cells are frozen in cryovials using slow-freezing protocols. However, this approach necessitates access to ultra-low temperature freezers and requires substantial storage capacity. This study aimed to evaluate the efficacy of a rapid-freezing protocol as a feasible alternative for the freezing of jaguar fibroblasts. Following cultivation to the third passage, cells were frozen using either slow-freezing (SF) or rapid-freezing (RF). For SF, cells were frozen in cryovials (-1 ºC/min), whereas RF involved rapid-freezing (-60 ºC/min) using nitrogen vapor and storage in 0.25 mL straws. Post-thaw, cells were re-cultured to assess recovery. Cell viability was assessed via light microscopy (Trypan blue), fluorescence microscopy (acridine orange + propidium iodide), and flow cytometry (Hoechst 33342 + propidium iodide) immediately post-thaw and upon reaching confluency (> 80%). Fresh culture viability assessed by Trypan blue, acridine orange, and flow cytometry was 98.2 ± 0.3%, 88.7 ± 3.9%, and 94.2 ± 2.2%, respectively. No significant differences in viability were observed between SF and RF immediately post-thaw or after subsequent cultivation. All three assays revealed significant differences (