RESUMEN
<p><b>OBJECTIVE</b>To establish a real-time quantitative PCR method for detecting the levels of the signal joint T cell receptor excision circles (sjTRECs) in murine thymocytes and spleen lymphocytes for determining the amount of naive T cells and evaluating the thymic function.</p><p><b>METHODS</b>The genomic DNA was extracted from murine thymocytes and splenocytes for PCR amplification of the target fragments. After purification of the PCR product, the recombination-activating gene 2 (RAG(2)) fragment was cloned into pGEMT-Easy vector to construct the standard plasmid. After PCR optimization, the standard curve was obtained and the samples (thymocytes and splenocytes of BALB/c and C(57)BL/6 mice) were detected for sjTRECs by real-time quantitative PCR.</p><p><b>RESULTS</b>The standard plasmid was correctly constructed, and the standard curve with high reliability was obtained. No statistical difference was observed in sjTREC contents in the T lymphocytes between the two mouse strains.</p><p><b>CONCLUSIONS</b>Real-time quantitative PCR for sjTREC analysis is established successfully, which offers an important means for thymic function analysis and a reliable model establishment for study the thymus.</p>