en ايمونولوژي Immunology پژوهشي Research <div style="text-align: justify;"><strong>Backgrounds </strong>Many proteins have been expressed so far in bacterial host. Due to its simple culture conditions, having a short life cycle, and easily genetic manipulation, <em>E.coli</em> have been regarded as a preferable host to produce recombinant proteins, but protein cloning in bacterial host have many challenges. Therefore, we aimed to review some of these problems by an experience from mice IL-2 recombinant.<br> <strong>Materials and methods: </strong>cDNA synthesis was performed after RNA extraction of mouse splenocytes. PCR product purification carried out after IL-2 coding sequence amplification and was ligated into the pET-21b (+) vector and transformed into the competent BL21 <em>E.coli</em>. Expression and purification of recombinant mouse IL-2 were done using IPTG inducer and metal affinity chromatography respectively.<br> <strong>Results:</strong> DNA sequencing confirmed the accuracy of the insertion process. A 23 kDa exogenous protein was observed on the SDS-PAGE. Specificity and concentration of produced mouse recombinant IL-2 protein were confirmed by western blotting and BCA methods.<br> <strong>Conclusion:</strong> Recombinant IL-2 was produced in BL21 and pET-21b (+) expression system at 24&deg;C in the soluble form.</div> Recombinant protein, pET-21b (+), IL-2 protein, Cloning 16 25 http://rmm.mazums.ac.ir/browse.php?a_code=A-10-1099-1&slc_lang=en&sid=1 Arezou Abdi arezou.abdiiii@mums.ac.ir 10031947532846007685 10031947532846007685 No ImmunoBiochemistry lab, Immunology Research Center, Mashhad University of medical Sciences, Mashhad, Iran Mitra Hosseinpour mitra.hossseinpourmmus@yahoo.com 10031947532846007686 10031947532846007686 No ImmunoBiochemistry lab, Immunology Research Center, Mashhad University of medical Sciences, Mashhad, Iran Kazem Mashayekhi kazemmashayekhiii@gmail.com 10031947532846007687 10031947532846007687 No ImmunoBiochemistry lab, Immunology Research Center, Mashhad University of medical Sciences, Mashhad, Iran Mohammad Javad Mousavi sm-mousavi@razi.tums.ac.ir 10031947532846007688 10031947532846007688 Yes Immunology Department, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Seyedeh Elham Badiee Kheirabadi elhambadiee.kheir@mums.ac.ir 10031947532846007689 10031947532846007689 No ImmunoBiochemistry lab, Immunology Research Center, Mashhad University of medical Sciences, Mashhad, Iran Mojtaba Sankian sankianmmm@mums.ac.ir 10031947532846007690 10031947532846007690 No ImmunoBiochemistry lab, Immunology Research Center, Mashhad University of medical Sciences, Mashhad, Iran