The One-Step qRT-PCR Kit are compatible with TaqMan probes. The Kit provides a convenient, sensitive, and reproducible method to detect and quantify the RNA molecules by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The components for cDNA synthesis, PCR amplification, and quantification are combined in a kit, using gene-specific primers, probes, and target RNAs from either total RNA or mRNA. The kit consists of three major components: RT/ HotStar Taq Mix, 2X Reaction Mix, and 50 mM Magnesium Sulfate (MgSO₄). The RT/ HotStar Taq Mix contain a mixture of Reverse Transcriptase (RTase) and HotStar Taq DNA polymerase for optimal cDNA synthesis and PCR amplification. The RTase is modified from the Moloney Murine Leukemia Virus (M-MLV) RTase, engineered to reduce RNase H activity and increase thermal stability. The HotStar Taq DNA polymerase is Taq DNA polymerase complexes with a proprietary antibody that blocks activity at ambient temperatures. Activity is restored after the enzyme activation step at 95°C, thereby providing an automatic “hot-start” for Taq DNA polymerase in PCR, increasing the sensitivity and specificity of PCR reaction. The 2X Reaction Mix consists of 6 mM MgSO₄, deoxyribonucleotide triphosphates (dNTPs), and stabilizers provide a proprietary buffer system optimized for reverse transcription and PCR amplification. One addition tube of 50 mM MgSO₄ is included in the kit. For COVID-19 detection, the optimal concentration is 4 mM. An additional 0.5 μl for each reaction is recommended.