Volume 6 Issue 7, July 2009

Two groups report culture conditions for long-term in vitro growth of intestinal tissue from the mouse.

An engineered infrared fluorescent protein is the first member of a new class of genetically encodable probes, with special advantages over visible-wavelength fluorescent proteins for in vivo imaging.

Computational and experimental biologists teamed up to develop a new software tool to analyze the rich data generated by new and powerful flow cytometers.

Grafting two transgenic plants triggers lateral gene transfer at the graft site but does not elicit long-distance transport of DNA into the scion or root of the graft.

A fluorescent probe designed to incorporate a fluorophore into the structure of a neurotransmitter finds activity-dependent heterogeneity in dopamine release at individual synapses.

Optical signatures from organic chemicals may help scientists detect traces of life on other planets.

An approach using multiple fluorochrome combinations allows the simultaneous detection of many T-cell populations within a single blood sample.

Sub-microsecond, downhill-reaction protein folding can be investigated by a method to generate large and fast pressure drops. The approach is complementary to nanosecond temperature-jump methods and could provide new insights into the biophysics of protein folding.

Mouse embryonic stem cell lines from the C57BL/6 strain are reported. The lines are highly germline competent, suitable for high-throughput genetic manipulation and will enable the generation of large knockout mouse resources.

Combinations of fluorescently labeled peptide–major histocompatability (pMHC) tetramers are used to simultaneously detect T cells with multiple antigen specificities from human blood samples. Also in this issue, Hadrup et al. present a very similar combinatorial encoding approach.

The protein interaction platform or PIP assay uses a viral scaffolding protein fused to a bait and a fluorescent reporter protein fused to putative prey as the basis for a simple visual screen for protein-protein interactions in yeast.

There have been many attempts to measure gene expression in single cells but counting several different mRNAs in the same cell has been a challenge. A reusable single-cell cDNA library immobilized on beads allows quantitative measurement of multiple mRNAs in a single cell with a large dynamic range and small experimental error.

Concatenated PCR products serve as subgenomic traps in this targeted genome capture technique; subsequent high-throughput sequencing allows the detection of nucleotide and structural variations in the captured genomic regions.

A combination of gradient refractive index lenses with plano-convex lenses produces high-resolution microlenses with image quality similar to a conventional high quality microscope objective. The microlenses are capable of imaging dendritic spines on hippocampal neurons in live mice.

Using a topographically patterned substrate for immobilization of single yeast cells and a piezo-impact micromanipulator to transiently disrupt the cell wall, molecules can be physically introduced into yeast.

Although fast temperature jump methods to study protein folding dynamics have long been applied, pressure has been a neglected thermodynamic parameter. A method to generate rapid and large drops in pressure is complementary to fast temperature jump methods and could be useful for direct comparisons to molecular dynamics simulations.

Using combinations of fluorescently labeled peptide–major histocompatability complex (pMHC) tetramers, T-cell populations with multiple antigen specificities can be monitored in parallel from small samples of human blood. Also in this issue, Newell et al. present a very similar combinatorial encoding method for this purpose.

Activation of caged doxycycline or cyanodoxycycline by biologically innocuous doses of UV light allows for precise temporal and spatial control of transgene expression in hippocampal slices, mouse embryos and Xenopus laevis tadpoles.

Fluorescence resonance energy transfer (FRET) between a small-molecule fluorophore donor and a transition metal ion acceptor, a method called 'transition metal ion FRET,' works over shorter distances than the classical FRET approach and can thus be used to monitor very small conformational changes in proteins.

Next-generation sequencing has made decoding entire genomes cheaper and faster. But what about those researchers who only want to sequence a small section of a genome or focus on a couple thousand specific exons? A wave of new technologies has recently emerged that should help these scientists target their sequencing efforts to sequences of interest.