排序方式: 共有24条查询结果,搜索用时 15 毫秒
21.
22.
Measurement of molecular diffusion in solution by multiphoton fluorescence photobleaching recovery 总被引:7,自引:2,他引:5
下载免费PDF全文
![点击此处可从《Biophysical journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Multiphoton fluorescence photobleaching recovery (MP-FPR) is a technique for measuring the three-dimensional (3D) mobility of fluorescent molecules with 3D spatial resolution of a few microns. A brief, intense flash of mode-locked laser light pulses excites fluorescent molecules via multiphoton excitation in an ellipsoidal focal volume and photobleaches a fraction. Because multiphoton excitation of fluorophores is intrinsically confined to the high-intensity focal volume of the illuminating beam, the bleached region is restricted to a known, three-dimensionally defined volume. Fluorescence in this focal volume is measured with multiphoton excitation, using the attenuated laser beam to measure fluorescence recovery as fresh unbleached dye diffuses in. The time course of the fluorescence recovery signal after photobleaching can be analyzed to determine the diffusion coefficient of the fluorescent species. The mathematical formulas used to fit MP-FPR recovery curves and the techniques needed to properly utilize them to acquire the diffusion coefficients of fluorescently labeled molecules within cells are presented here. MP-FPR is demonstrated on calcein in RBL-2H3 cells, using an anomalous subdiffusion model, as well as in aqueous solutions of wild-type green fluorescent protein, yielding a diffusion coefficient of 8.7 x 10(-7) cm(2)s(-1) in excellent agreement with the results of other techniques. 相似文献
23.
EB Adamah-Biassi Y Zhang H Jung S Vissapragada RJ Miller ML Dubocovich 《The journal of histochemistry and cytochemistry》2014,62(1):70-84
The pineal hormone melatonin activates two G-protein coupled receptors (MT1 and MT2) to regulate in part biological functions. The MT1 and MT2 melatonin receptors are heterogeneously distributed in the mammalian brain including humans. In the mouse, only a few reports have assessed the expression of the MT1 melatonin receptor expression using 2-iodomelatonin binding, in situ hybridization and/or polymerase chain reaction (PCR). Here, we described a transgenic mouse in which red fluorescence protein (RFP) is expressed under the control of the endogenous MT1 promoter, by inserting RFP cDNA at the start codon of MTNR1a gene within a bacterial artificial chromosome (BAC) and expressing this construct as a transgene. The expression of RFP in the brain of this mouse was examined either directly under a fluorescent microscope or immunohistochemically using an antibody against RFP (RFP-MT1). RFP-MT1 expression was observed in many brain regions including the subcommissural organ, parts of the ependyma lining the lateral and third ventricles, the aqueduct, the hippocampus, the cerebellum, the pars tuberalis, the habenula and the habenula commissure. This RFP-MT1 transgenic model provides a unique tool for studying the distribution of the MT1 receptor in the brain of mice, its cell-specific expression and its function in vivo. 相似文献
24.
Pregnancy block in mice requires exposure of recently mated females to
urinary pheromones of a strange male, and when working with inbred strains
this invariably requires urine from an outbred line. The pheromones which
induce oestrus and early puberty in mice have been identified as the
brevicomins and dihydrothiazoles. Since the same vomeronasal, neural and
neuroendocrine pathways are also activated in pregnancy block, these
compounds are likely candidates for pregnancy blocking pheromones. However,
these relatively simple chemicals lack the capacity to code for differing
mouse strains. Since large quantities of the polymorphic major urinary
proteins from the lipocalin family found in urine serve as transporters for
the dihydrothiazoles and brevicomins, and differ across strains, then these
proteins must participate in pheromone recognition in the context of
pregnancy block.
相似文献