Semi-Quantitative RT-PCR: An Effective Method to Explore the Regulation of Gene Transcription Level Affected by Environmental Pollutants.

Semi-quantitative reverse transcription and polymerase chain reaction (sqRT-PCR) is a simple and specific method for quantitative RNA in recent years. The relative quantity of a specific mRNA in the samples can be inferred by reverse transcription of mRNA into cDNA, and PCR amplification and determination of the quantity of PCR products. The semi-quantitative analysis is carried out under a fixed number of PCR cycles, and the total RNA concentration is kept in the exponential phase of the PCR. The method is to use a housekeeping gene (usually actin, GAPDH, and EF1α) as a reference standard in treated and control organisms to observe the expression of the interested genes (upregulated or downregulated) in toxicology. In this chapter, we describe a step-by-step method for determining the differential regulation of target genes in organisms exposed to environmental pollutants.