Simple procedure for production of short DNA size markers of 100 to 2000 bp

Document Type : Original Research Papers



DNA size markers (ladder) are essential tools in molecular biology, genetics and biotechnology. In this study, a simple and cost-effective method for laboratory production of DNA ladders is introduced. For this purpose, different sizes of 100 to 2000 bp DNA segments were designed using PCR technique. For producing 14 different gene fragments as DNA molecular weight markers, recombinant plasmid pET28a containing α-amylase gene as a DNA source and one forward and 14 reverse primers were used. The gene fragments containing 100 to 400bp segments with a distance of 50 bp and 400 to 1600 bp segments with a distance of 200 bp as well as 1600 to 2000 bp segments with the distance of 400 bp were generated in a single run of PCR. The present technique could prove to be simple, time saving, inexpensive and good quality approach as compared to the usual DNA ladder preparation procedures. Also, according to the same conditions for designed primers there is a possibility of producing other marker sizes by choosing different types of forward and reverse primers. The PCR product mixture could be directly loaded onto the agarose gel and used as a molecular weight marker without further purification because that was as reliable and uniform as markers from commercial sources. Finally, this marker can be useful for most of molecular biology laboratory techniques.