A new fluorometric method for RNA and DNA determination
Previous studies have shown that a dye, ethidium bromide, markedly increases its fluorescence when it binds to double-stranded DNA or double-stranded regions of RNA. It is shown that, in the given conditions, a linear relationship between fluorescence and nucleic acid concentration is obtained. Thus, a new spectrofluorometric method for determining DNA and RNA using this principle is described. This method is specific for nucleic acids, can be used over a wide range of salt concentrations, and has a good sensitivity (0.01 μg/ml of DNA). No biological compounds able to interfere have been found. An adaptation of this method for determining both DNA and RNA in a mixture is also described.
 Multiple Forms of DNA-dependent RNA Polymerase in Eukaryotic Organisms
Three distinct RNA polymerase activities have been isolated from developing sea urchin embryos. In rat liver nuclei there are two RNA polymerase activities. One polymerase (I) is probably localized in the nucleolus and one (II) in the nucleoplasm.
 Nanoparticles with Raman Spectroscopic Fingerprints for DNA and RNA Detection
Multiplexed detection of oligonucleotide targets has been performed with gold nanoparticle probes labeled with oligonucleotides and Raman-active dyes. The gold nanoparticles facilitate the formation of a silver coating that acts as a surface-enhanced Raman scattering promoter for the dye-labeled particles that have been captured by target molecules and an underlying chip in microarray format. The strategy provides the high-sensitivity and high-selectivity attributes of gray-scale scanometric detection but adds multiplexing and ratioing capabilities because a very large number of probes can be designed based on the concept of using a Raman tag as a narrow-band spectroscopic fingerprint. Six dissimilar DNA targets with six Raman-labeled nanoparticle probes were distinguished, as well as two RNA targets with single nucleotide polymorphisms. The current unoptimized detection limit of this method is 20 femtomolar.
 Single Subunit RNA Polymerases: An Insight into their Active Sites and Catalytic Mechanism
Aim: To analyze various single subunit DNA dependent RNA polymerases and identify conserved motifs, active site regions among them and propose a plausible mechanism of action for these polymerases using the T7 RNA polymerase as a model system.
Study Design: Bioinformatics, Biochemical, Site-directed mutagenesis and X-ray crystallographic data were analyzed.
Place and Duration of Study: Department of Molecular Microbiology, School of Biotechnology, Madurai Kamaraj University, Madurai – 625 021, India, from 2010 to 2013.
Methodology: The advanced version of Clustal Omega was used for protein sequence analysis of various SSU DNA dependent RNA polymerases from viruses, mitochondria and chloroplasts. Along with the conserved motifs identified by the bioinformatics analysis and with the data obtained by X-ray crystallographic, biochemical and site-directed mutagenesis were also used to confirm the possible amino acids involved in the active sites and catalysis of these RNA polymerases.
Results: Multiple sequence analyses of various single subunit (SSU) DNA dependent RNA polymerases from different sources showed only a few highly conserved motifs among them, except chloroplast RNA polymerases where a large number of highly conserved motifs were found. Possible catalytic regions in all these polymerases consist of a highly conserved amino acid K and a ‘gate keeper’ YG pair. In addition to, these polymerases also use an invariant R at the -4 position from the YG pair and an invariant S/T, adjacent to the YG pair. Furthermore, two highly conserved Ds are implicated in the metal binding site and thus might participate in the catalytic process. The YG pair appears to be specific for DNA templates as it is not reported in RNA dependent RNA polymerases.
Conclusion: The highly conserved amino acid K, the ‘gate keeper’ YG pair and an invariant R which are reported in all DNA polymerases, are also found in these DNA dependent RNA polymerases. Therefore, these RNA polymerases might be using the same catalytic mechanism like DNA polymerases. The catalytic amino acid K could act as the proton abstractor and generate the necessary nucleophile at the 3’-OH and the YG pair, R and the S/T might involve in the template binding and selection of nucleoside triphosphates (NTPs) for polymerization reactions. The two highly conserved Ds could act as the ‘ NTP charge shielder’ and orient the alpha phosphate of incoming NTPs for reaction at the 3’-OH growing end.
 DNA Sequence Characteristics and Phylogenetics of Three Oligonucleotides Markers on Clariid Species
Aims: The aim of this study is to express the profiles of three oligonucleotide markers corresponded to reproductive genes that may be different between the two Clariid species (Clarias gariepinus and Heterobranchus bidorsalis) and their phylogenetics.
Methodology: Total DNA isolation was carried out on the whole blood of the two strains of Clariid species – 100 species Clarias gariepinus male and female (1.2 – 1.5 kg, 34 – 52 cm) separately; 100 species Heterobranchus bidorsalis (1.7 – 2.2 kg, 38 – 60 cm) respectively using the Quick-gDNA Zymo research kit. Having ascertained the DNA stability on 0.8% agarose gel, NCBI database and Clustal analyses were employed to design primers to reproductive genes that may be different between the two catfishes and may participate in their differential reproducibility. We have used quantitative real-time PCR to investigate the expression of three selected oligonucleotides markers on the catfish. CLC Sequence viewer 7 software was used to analyze the nucleotide alignment percentage and develop the phylogenetics tree.
Place and Duration of Study: The study was carried out in the Biotechnology Centre, Federal University of Agriculture, Abeokuta Nigeria between January and July 2014.
Results: We observed a dimorphic expression pattern of the three marker genes in relation to strains and sex differentiation, indicating that sox9a retained its function in testis, Figα was highly expressed in the female and Cyp19a1b was up-regulated in male C. gariepinus than male H. bidorsalis catfish species. The phylogenetic tree showed that male Heterobranchus and female Clarias were closer irrespective of male or female while male Clarias differed from the two.
Conclusion: To date, these three genes, Sox 9a, Figα and Cyp19a1b have been detected in many fishes, but little or no data has been reported in African catfishes. The findings from this study might be used as the target gene for catfish gender regulation.
 Le Pecq, J.B. and Paoletti, C., 1966. A new fluorometric method for RNA and DNA determination. Analytical biochemistry, 17(1), pp.100-107.
 Roeder, R.G. and Rutter, W.J., 1969. Multiple forms of DNA-dependent RNA polymerase in eukaryotic organisms. Nature, 224(5216), pp.234-237.
 Cao, Y.C., Jin, R. and Mirkin, C.A., 2002. Nanoparticles with Raman spectroscopic fingerprints for DNA and RNA detection. Science, 297(5586), pp.1536-1540.
 Palanivelu, P., 2017. Single subunit RNA polymerases: An insight into their active sites and catalytic mechanism. Biotechnology Journal International, pp.1-35.
 Agbebi, O.T., Oyelakin, O.O., Adebambo, O.A. and Abduraheem, I., 2016. DNA Sequence Characteristics and Phylogenetics of Three Oligonucleotides Markers on Clariid Species. Biotechnology Journal International, pp.1-7.