关键词: 血液PCR；鸡早期胚胎；性别鉴定；超保真酶

Abstract: To solve the problems of complex operation and high cost of traditional PCR methods for early chicken embryos，this study aimed to establish a rapid PCR detection technology based on trace blood samples， so as to provide a new method for optimizing the PCR identification of early poultry embryos.［Methods］Chicken embryos at three incubation time points（6.5，8.5，and 10.5 days）were selected，and primers for sex identification genes，germ cell marker genes，and housekeeping genes were designed for the experiment. Comparative experiments were carried out simultaneously，including traditional tissue DNA extraction，rapid DNA extraction，and direct PCR dete ction with trace blood samples aspirated as templates，and the amplification efficiencies of three types of PCR premixes were compared.［Results］The experimental results showed that：（1）The PCR identification results of trace blood were consistent with those of the traditional tissue DNA extraction method，with an accuracy rate of 100%；（2） The optimized PCR identification system did not need to add PCR enhancers and stabilizers，and whole blood samples could be directly used as templates after dilution，which significantly reduced the detection cost per sample. ［Conclusion］The direct PCR method using trace blood from early chicken embryos established in this study can replace the traditional DNA extraction identification method，which greatly shortens the time and simplifies the operation steps，and significantly improves work efficiency while maintaining 100% accuracy. This technology has the advantages of rapidity，convenience，low cost and reliable results，providing an innovative solution for the PCR identification of poultry embryos.

Key words: Blood PCR；Early chicken embryo；Sex identification；Ultra?fidelity enzyme