Volume 6 Issue 4, April 2009

Super-resolution fluorescence microscopy gets a boost in axial resolution from two groups of optics wizards.

By covalently attaching cyclodextrin to a hemolysin nanopore, researchers show single-molecule, label-free sequencing at very high accuracy.

Combining ribosome profiling and deep sequencing, researchers present a method to monitor protein translation genome-wide.

Two groups extend the boundaries of in-cell nuclear magnetic resonance spectroscopy.

A long-range magnetic resonance imaging platform promises unprecedented capabilities for whole-organ visualization and high-throughput sample analysis.

With the addition of a ligand-sensing aptamer sequence, a self-replicating RNA enzyme system enables general molecular detection, analogous to that of quantitative PCR.

Some scientists suggest that environmental standardization may lead to spurious findings. The implication from this hypothesis will likely be controversial.

Deep sequencing of DNase I–treated yeast DNA yields genome-wide information on chromatin transitions as well as protein binding in these regions.

The base-calling algorithm SNPSeeker detects single-nucleotide polymorphisms with frequencies that are below the error rate of the sequencing platform. It is thus well suited to analyze data from large pooled samples and find rare variants that may contribute to diseases or complex traits.

Long-term engraftment of hematopoietic stem cells into the bone marrow of a recipient depends on immunological compatibility between donor and host, or ablation of the host's immune system by irradiation. A 'universal recipient' mouse model now shows that mice that lack T, B and NK cells and bear mutations in the tyrosine kinase Kit accept any donor HSC without irradiation.

Rats are desensitized to xenografts of human neural or embryonic stem cell–derived cells by exposure to the xenogeneic cells during the neonatal period. Brain grafts survive in immunocompetent rats without chronic immunosuppression, allowing long-term studies.

As an alternative to the use of radioactively labeled amino acids, incorporation of puromycin into proteins allows evaluation of translation in heterogenous cell populations by flow cytometry analysis after staining with an antibody to puromycin.

Complex three-dimensional structures on cellular surfaces are often damaged during high-resolution imaging of live cells. Now, hopping probe scanning ion conductance microscopy—which uses a hopping nanopipette that 'hops' instead of 'sliding'—protects surface structures from probe-induced damage.

Dense mapping of DNase I cleavage sites across the whole yeast genome by next-generation sequencing reveals a global view of the binding of regulatory proteins to genomic DNA. The high resolution allows the identification of new binding sites for known factors as well as the de novo derivation of factor binding motifs.

The PCR step in the preparation of sequencing libraries for the Illumina Genome Analyzer can introduce coverage bias, especially in very (A+T)-rich genomes. By directly annealing template DNA to adapters with sequences needed for attachment in the flow cell, PCR can be omitted as cluster amplification in the flow cell enriches for fully ligated templates.

An automated system to measure aggression and courtship in pairs of interacting Drosophila is presented and should allow large-scale screens of these behaviors in the future.

From high-throughput electroporation platforms capable of transfecting thousands of different cells in a day, to nanowires that puncture and deliver DNA to just a single cell, new technology is emerging to help researchers with their changing gene delivery needs.