Summary of the April 2014 Issue of BioTechniques
The April 2014 issue of BioTechniques will feature new articles describing novel methods developments in the areas of DNA nanostructure assembly, cell culture design, droplet digital PCR function, and molecular cloning. In addition to these research articles, April will also feature news articles profiling major figures in scientific research, a collection of highlights of the best new methods and techniques, and a Tech News article focusing on recent major developments in the field of stem cell biology.
In many cell biology studies, glass coverslips serve as a substrate for cell culture wherein extracellular matrix proteins have been deposited. In a study in the April issue of BioTechniques, researchers from Japan demonstrate that the use of a specialized coating on the glass surface of a coverslip resulted in improved motility and cell morphology in comparison to non-treated glass surfaces. The results should assist researchers in working to create a more suitable culture substrate for cells when observing the physiological effects of extracellular matrix components.
Self-assembly of designed DNA molecules has been demonstrated to result in useful nanoscale structures. In April, researchers describe a new computational algorithm capable of identifying sets of strand sequences optimized for self-assembly into specific nanoscale structures. The authors designed several different structures to validate their program and procedure.
Cell-free protein synthesis is a robust and versatile method for the production of recombinant proteins. A drawback to the cell-free approach is the need to store cell extracts or generate cell extracts prior to the protein synthesis reaction. In a Report in the April issue, a research team from Brigham Young University describes a method for lyophilizing cell extracts into a powder for long-term storage and use in protein production. The authors demonstrate that lyophilized cell extracts are stable for longer periods than their aqueous counterparts while generating more recombinant protein following long-term storage. This new approach to cell extract storage should enhance the use of cell-free protein synthesis systems for all researchers.
Droplet digital PCR is rapidly becoming a major technique for researchers interested in studying gene structure and expression. One issue for those using droplet digital PCR to study genomic DNA samples, however, is the viscosity of genomic DNA, which can interfere with the partitioning of samples into individual reaction droplets. Many researchers have turned to restriction enzymes to digest DNA prior to droplet partitioning but this technique leaves excess reaction buffer and enzyme that can lead to problems during amplification. To address this issue, researchers from the University of California, San Francisco report on the use of fragmentation as an alternative in the April issue of BioTechniques. Rather than use restriction digests, the authors demonstrate that fragmentation using a spin column is faster and actually results in more predictable and uniformly sized fragments than restriction enzymes. This straightforward new technique should further reinforce the growing utility of droplet digital PCR for molecular biologists.
For genetic manipulations, selectable markers are key. And drug selection markers are arguably the most powerful, and commonly used, markers by molecular biologists. But there is a limit to the number of markers many researchers have available in their labs, which has led some to attempt to remove selection markers. In a Benchmark slated for the April issue, researchers from China demonstrate that by using the newly developed CRISPR/Cas system, it is possible to remove an antibiotic resistance gene previously used to select for a cell line – without the requirement for pre-engineered sequences, such as loxP or FRT. This technique provides an additional, and powerful, means for researchers to remove selection markers when attempting to make stable cells, and will be another useful tool in the molecular biology toolkit.
Keywords: CRISP/Cas, selectable markers, digital PCR, genomic DNA, copy number analysis, recombinate proteins, cell-free protein synthesis, proteomics, Western blots, DNA nanostructures, computational biology, DNA self assembly, cell culture, extracellular matrix, glass slide coatings, stem cell biology, stem cell analysis, molecular biology