Home » Science » Biochemistry

Category Archives: Biochemistry

Advertisements

A New Era in Molecular Biology: “CRISPR/Cas9” and Targeted Gene Editing

A New Era in Molecular Biology: CRISPR/Cas9 and Targeted Genome Editing

GenomeEditing

The development of efficient and reliable ways to make precise, targeted changes to the genome of living cells is a long-standing goal for biomedical researchers. Recently, a new tool based on a bacterial CRISPR-associated protein-9 nuclease (Cas9) from Streptococcus pyogenes has generated considerable excitement. This follows several attempts over the years to manipulate gene function, including homologous recombination and RNA interference (RNAi). RNAi became a laboratory staple enabling inexpensive and high-throughput interrogation of gene function but it is hampered by providing only temporary inhibition of gene function and unpredictable off-target effects. Other recent approaches to targeted genome modification – zinc-finger nucleases (ZFNs), and transcription-activator like effector nucleases (TALENs) enable researchers to generate permanent mutations by introducing doublestranded breaks to activate repair pathways. These approaches are costly and time-consuming to engineer, limiting their widespread use, particularly for large scale, high-throughput studies

The functions of CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and CRISPR-associated (Cas) genes are essential in adaptive immunity in select bacteria and archaea, enabling the organisms to respond to and eliminate invading genetic material. These repeats were initially discovered in the 1980s in E. coli, but their function wasn’t confirmed until 2007 by Barrangou and colleagues, who demonstrated that S. thermophilus can acquire resistance against a bacteriophage by integrating a genome fragment of an infectious virus into its CRISPR locus. Three types of CRISPR mechanisms have been identified, of which type II is the most studied. In this case, invading DNA from viruses or plasmids is cut into small fragments and incorporated into a CRISPR locus amidst a series of short repeats (around 20 bps). The loci are transcribed, and transcripts are then processed to generate small RNAs (crRNA – CRISPR RNA), which are used to guide effector endonucleases that target invading DNA based on sequence complementarity.

Advertisements

DNA Metabarcoding: A Rapid Method for Biodiversity Assessment

DNA-metabarcoding2-2a

DNA metabarcoding refers to the automated identification of multiple species from a single bulk sample containing entire organisms. This offers unprecedented scientific and operation opportunities in order to understand biodiversity distribution and dynamics in a better way. Managing the health of global ecosystems requires detailed inventories of species and a good understanding of the patterns and trends of biodiversity. Evolutionary and ecological studies often rely on our ability to identify the species involved in the process under investigation or our capacity to provide robust biodiversity estimates. For about three centuries, the acquisition of biodiversity data was based on morphological characterization of plants and animals. The idea of identifying species on the basis of molecular markers emerged soon after the advent of molecular biology. Early methods involved the use of hybridization, restriction enzyme digestion or other molecular probes. DNA-based species identification was introduced by Arnot et al. and further development, standardized and advanced by Hebert et al. The ability to extract and store DNA for prolonged periods of time provides a unique opportunity to assess the evolution of biodiversity over time in relation to global change and to develop concrete measures to reserve these features. For more details, please click here.
DNA Metabarcoding

Genetic Improvements of traits for enhancing NPK Acquisition and Utilization Efficiency in Plants

Book title: Plant Macronutrient Use Efficiency: Molecular and Genomic Perspectives in Crop Plants

Editors: Mohammad Anwar Hossain, Takehiro Kamiya, David J. Burrit, Lam-Son Phan Tran and Toru Fujiwara

Publisher: Academic Press, Elsevier

Mybook

Genetic Improvements of traits for enhancing NPK Acquisition and Utilization Efficiency in Plants

Inductively Coupled Plasma-Mass Spectrometry : A Rapid Technique for Multi-Elements Determination at the Ultra-Trace Level

 

20150707_161353a

Inductively coupled plasma mass spectrometry (ICP-MS) is a type of mass spectrometry which is capable of detecting metals and several non-metals at concentrations as low as one part per trillion. ICP-MS is undoubtedly the fastest growing trace element technique available today. It allows determination of elements with atomic mass ranges 7 to 250. It is able to detect the elements upto part per trillion levels and this ability to carry out rapid multi-elements  determination at the ultra-trace level  have made it very popular in diverse range of applications areas  including environment, geochemical, semiconductor, metallurgical, nuclear, chemical, climatic and biotechnology. In recent years, industrial and biological monitoring has presented major need for metal analysis by ICP-MS. Other uses is in the medical and forensic field, specifically, toxicology and heavy metal poisoning.

For basics of ICP-MS working, please click on the following link…..

https://wordpress.com/page/gingerfingers.wordpress.com/438

 

%d bloggers like this: