RESUMO
iNOS is inducible by a variety of factors related to inflammation and referred to as inducible NOS[iNOS]. It is regulated at the level of gene expression; once expressed, it produces NO at a high rate. iNOS gene-expression profiling is an important tool in understanding molecular markers of the responses of cells and tissues to external factors. In this article a semiquantitative reverse transcription-polymerase chain reaction [RT-PCR] protocol was optimized to extract RNA [ribonucleic acid] from chicken spleen and to measure the expression levels of iNOS mRNAs from each sample. Detailed procedure was described for the analysis of iNOS levels. beta-actin was used as an internal control to normalize for sample to sample variations in total RNA amounts and for reaction efficiency. Co-amplification of the iNOS gene with housekeeping gene [beta-actin] provides a quantitative result. Changes in gene expression level may be monitored, while avoiding sample-to-sample loading variation