title: Cell-free cloning using multiply-primed rolling circle amplification with modified RNA primers.
abstract: The predominant method for DNA cloning is by propagation in biological hosts, but this method has limitations because certain sequences are difficult to clone using any combination of available hosts or vectors. Recently, multiply-primed rolling circle amplification (MPRCA) has been applied to overcome the problems of the DNA cloning via host cells. However, when MPRCA is used to amplify from minute quantities of DNA template, the products are mostly by-product DNA molecules generated by false priming and primer dimer formation. This study demonstrates that MPRCA using random RNA primers[#x02014]instead of DNA primers[#x02014]blocked the synthesis of by-products and succeeded in amplifying one copy of a circular DNA molecule more than 1012-fold to give microgram quantities of amplification product without using submicroliter reaction volumes. Furthermore, a ligation strategy was elaborated to circularize only the desired DNA sequence and eliminate undesired ligation-products. A combination of these methods was able to amplify and ligate a large construct without undesired DNA sequences and at microgram quantities within one day. Therefore, these methods have the possibility to improve DNA cloning techniques that have been restricted by the limitations of PCR methods or by the host cell.
authors: NanoBiotechnology Laboratory, Food Engineering Division, National Food Research Institute, National Agriculture and Food Research Organization, Ibaraki, Japan.
authors: Hirokazu
authors: H
authors: Takahashi
authors: Kimiko
authors: K
authors: Yamamoto
authors: Toshio
authors: T
authors: Ohtani
authors: Shigeru
authors: S
authors: Sugiyama
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D010582:Bacteriophage lambda / Q000737:chemistry; D001483:Base Sequence; D002474:Cell-Free System; D003001:Cloning, Molecular; D011088:DNA Ligases / Q000378:metabolism; D004270:DNA, Circular / Q000235:genetics*; D004279:DNA, Viral / Q000235:genetics; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism; D005092:Exonucleases / Q000378:metabolism; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012313:RNA / Q000737:chemistry / Q000235:genetics*; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D013698:Templates, Genetic; D014764:Viral Proteins / Q000378:metabolism
chemical_list: D052157:Aptamers, Nucleotide; D004270:DNA, Circular; D004279:DNA, Viral; C034477:RNA primers; D014764:Viral Proteins; D012313:RNA; D004259:DNA-Directed DNA Polymerase; D005092:Exonucleases; D011088:DNA Ligases