细胞功能测定

Oocytes from the Xenopus laevis represent one of the most widely used expression systems for functional characterization of ion channels. Their large size facilitates both injection of heterologous cRNA and subsequent electrophysiological recordings of ion channel currents. ...

Species identification in microbiology has long been hampered by the limits of pure culture techniques. This is most evident in cases where morphologically conspicuous microorganisms have so far resisted all attempts of enrichment and cultivation like for many of the numerous endos ...

The principle of subtraction hybridization protocols is the removal from one cell type of nucleic acid sequences that are shared with other cell types (sources of subtracter sequences), to leave only sequences unique to the cell type or organism in question. Subtracter sequences may be from o ...

The functional activity of ion channels is affected by their local environment, and for certain types of channels this local effect is critical. This chapter describes a method of recording the activity of ATP-sensitive K+ channels, expressed on the plasma membrane of pancreatic β-cells, wi ...

Ion channels have gained increased interest as therapeutic targets over recent years, since a growing number of human and animal diseases have been attributed to defects in ion channel function. Potassium channels are the largest and most diverse family of ion channels. Pharmaceutical a ...

A number of recent studies have described the activation of BKCa channels by steroid hormones such as estrogen. The proposed mechanisms are diverse and include both the direct interaction with the ion channel subunits and the stimulation via receptor activation and cell signalling path ...

Bioluminescence Resonance Energy Transfer (BRET) measures protein interactions within 10 nm of each other. Aside from its ability to probe for interactions at high resolution, this technique operates in live, intact cells, and offers a high throughput method of detection. Thus far, BRET h ...

while X-ray crystallography provides extremely high-resolution snapshot of protein structure, it lacks the ability to provide dynamic information on the processes involving conformational rearrangements of the protein. Methods to record protein conformational dynami ...

Ion channels are the cell's gatekeepers. These proteins selectively allow ionic current to flow down its electrochemical gradient. In some cases, specialized chemical or voltage sensing domains respond to environmental changes and signal the cell to adjust its internal chemistry in r ...

The application of antibodies to living cells has the potential to modulate the function of specific proteins by virtue of their high specificity. This specificity has proven effective in determining the involvement of many proteins in neuronal function where specific agonists and an ...

The beta-cell ATP-sensitive potassium channel is a key component of stimulus —secretion coupling in the pancreatic beta-cell. The channel consists of four subunits of the inwardly rectifying potassium channel Kir6.2 and four subunits of the sulfonylurea receptor 1. Loss of function mu ...

Small-conductance Ca2+−activated potassium (SK) channels constitute a family of ion channels that are regulated by the cytosolic Ca2+ concentration. Increases in the intracellular Ca2+ concentration (i) result in opening of the channels, which in turn will lead to changes in the membra ...

The complex gating of the hERG channel makes it ideally suited to its principal role in controlling phase 3 repolarization of the cardiac ventricular action potential. Any abnormal delay in repolarization can lead to the re-activation of Ca2+ channels, giving rise to early after-depolari ...

This chapter describes a method of assaying rubidium (Rb+) efflux as a measure of potassium channel activity. In this assay, rubidium acts as a tracer for potassium movement across the cell membrane. HEK 293 cells expressing the alpha subunit of the human brain large-conductance, voltage-act ...

Fungi are an incredibly diverse and nearly ubiquitous group of eukaryotes. Estimates put their numbers higher than 1.6 million species (1). They have been identified traditionally by morphological differences in their sexual or asexual reproductive structures. However, such stru ...

The sensitivity of the polymerase chain reaction (PCR) (1,2), coupled to the specificity afforded by taxon-specific primers allows the analysis of a variety of samples, like minute amounts of cultured organisms (3, 4), or even endosymbionts like the endomycorrhizal fungi present in the roo ...

Among the different methods devised to detect genetic polymorphisms, the analysis of single-strand conformation is simple and yet exquisitely sensitive (1–5). It has been reported that even single base substitution can be detected between DNA fragments ranging in size from 100–450 bp (3). ...

The basic polymerase chain reaction (PCR) (1), which consists of the exponential amplification of DNA fragments between terminal sequences recognized by specific oligonucleotide primers, is a very powerful method but does not satisfy all wishes. The need for sequence information fr ...

Questions regarding species identification, differentiation, and relationships often emerge in biological investigations. One may need to examine the extent of genetic relationships between closely related species for the purposes of resource management or assessment of ...

Leishmaniasis is a parasitic disease that is difficult to diagnose. This IS owing to the low number of parasites observed in clinical samples and the similarity of parasites that cause different clinical symptoms. Previously, culturing was necessary to identify the parasites with tech ...