Addressing species identification of 12 animals and human beings with two novel assays

The strong interaction between animals and humans in life makes the application of animal DNA analysis increasingly valuable. To determine the species origin of biological samples from crime scenes, exclude extraneous samples and focus on key evidence, and to identify meat adulteration incidents in food markets, two novel systems were developed to address the issue in this study. Both systems allow simultaneous identification of human beings (Homo sapiens) and 12 common animal species (Canis lupus familiaris, Felis catus, Gallus gallus, Anas platyrhynchos, Bos taurus, Ovis aries, Sus scrofa, Oryctolagus cuniculus, Equus caballus, Micropterus salmoides, Columba livia, Mus musculus) based on species-specific short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs), respectively. To validate the efficacy of the two systems in practical cases, we conducted a series of validation experiments on sensitivity, species specificity, mixture detection, and special case sample tests. Both were validated for the detection of blood, buccal swabs, tissue, and bloodstain samples. They showed good species specificity and are capable of identifying different species in mixed samples. They also have considerable detection rates for degraded samples after cooking and UV irradiation. Two systems provide more options for animal species identification based on the diversity and complexity of biological samples.