The preservation of animal organs for educational and anatomical research purposes has traditionally relied on formaldehyde, a compound known for its effectiveness but also for its high toxicity. In the study conducted at the Animal Anatomy Laboratory of the Central University of Ecuador, an alternative technique was implemented using solutions composed of ethyl alcohol, acetic acid, sodium chloride, sorbic acid, and propylene glycol, aiming to develop a safe and effective preservation method. Organs from bovine, canine, porcine, and avian sources were used. Throughout the 6- and 18-month observation periods, no microbiological contamination, particularly fungal growth, was detected in bovine (heart and kidneys) and canine (heart with trachea and lungs) specimens. The combination of ethyl alcohol as a dehydrating agent, propylene glycol as a humectant, and acetic acid as a preservative contributed to reducing health risks for laboratory personnel and minimizing environmental impact. However, the technique yielded suboptimal results with avian and porcine organs, with microbial contamination linked to sourcing from small-scale retail markets. Consequently, the alcohol–propylene glycol method is considered a viable option for animal organ preservation, provided that certain measures are adopted to ensure its effectiveness, such as regular microbiological environmental monitoring and sourcing organs from certified slaughterhouses that maintain cold chain and traceability standards.

KEY WORDS: Acetic acid; Alternative; Microbiological control; Formaldehyde.