The use of housekeeping genes (HKG) as an internal control for the detection of gene expression by quantitative real-time RT-PCR.

Quantitative real-time RT-PCR is a very useful technique for estimating gene expression at the mRNA level. The expression of a tested gene has to be compared with that of a control gene. Various housekeeping genes have been used as control genes in different systems. In our study we tested several housekeeping genes in the model of gene expression after induction of apoptosis and differentiation. The myeloid cell lines were incubated with phorbol esters, butyric acid and combination of TNFalpha and IFNgamma to induce differentiation. Camptothecin was used for induction of apoptosis. Tested control genes included beta2-microglobulin, GAPDH, 18S ribosomal RNA and abl. GAPDH was found to be the best control gene in the apoptotic system. Different control genes were suitable for different systems where differentiation or senescence was induced. Our results show that attention should be paid to the choice of an appropriate control gene of quantitative real-time RT-PCR for different experimental models and various experimental conditions.