科研之友
微信
新浪微博
Facebook
分享链接
摘要
Cauliflower-like DNAs are stem-loop DNAs that are fabricated periodically in inverted repetitions from deoxyribonucleic acid phosphates (dNTPs) by loop-mediated isothermal amplification (LAMP). Cauliflowerlike DNAs have ladder-shape behaviors on gel electrophoresis, and increasing the time of LAMP leads to multiplying the repetitions, stem-loops, and electrophoretic bands. Cauliflower-like DNAs were fabricated via LAMP using two loop primers, two bumper primers, dNTPs, a λ-phage DNA template, and a Bst DNA polymerase in 75- and 90-min periods. These times led to manufacturing two types of cauliflower-like DNAs with different contents of inverted repetitions and stem-loops, which were clearly indicated by two comparable electrophoresis patterns in agarose gel. LAMP-fabricated DNAs and natural dsB-DNA (salmon genomic DNA) were dialyzed in Gomori phosphate buffer (10 mM, pH 7.4) to be isolated from salts, nucleotides, and primers. DialyzedDNAswere studied usingUVspectroscopy, circular dichroism spectropolarimetry, and fluorescence spectrophotometry. Structural analyses indicated reduction of the molecular ellipticity and extinction coefficients in comparison with B-DNA. Also, cauliflower-like DNAs demonstrated less intrinsic and more extrinsic fluorescence in comparison with natural DNA. The overwinding and lengthening of the cauliflower-like configurations of LAMP DNAs led to changes in physical parameters of this type of DNA in comparison with natural DNA. The results obtained introduced new biomolecular characteristics ofDNAmacromolecules fabricated within aLAMPprocess and show the effects of more inverted repeats and stem-loops, which are manufactured by lengthening the process.
