- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Aptamers Improving Fluorescence Anisotropy and Fluorescence Polarization Assays for Small Molecules
摘要： Nucleic acid affinity probes, such as aptamers, have been combined with fluorescence anisotropy (FA) / fluorescence polarization (FP) technology for the development of a diverse range of assays. Formation of a complex between a small fluorescent molecule and its binding partner usually increases the overall size of the fluorescent molecule and decreases its rate of rotation, resulting in increases in fluorescence anisotropy/polarization. Structure-switching of the fluorescently labeled aptamers arising from target binding can also affect molecular volume, local rotation of the fluorophore, and/or fluorescence lifetime, causing changes in anisotropy/polarization. Incorporation of the unique adsorptive properties of single-stranded nucleic acid aptamers on nanomaterials, hybridization of aptamers with complementary sequences, and the amplifiable ability of nucleic acid aptamers have broadened the applications of fluorescence anisotropy assays and enhanced their sensitivity. This review focuses on aptamer-based fluorescence anisotropy assays for the detection of small molecules, such as therapeutic drugs, environmental contaminants, natural toxins, and metabolites.
关键词： aptamer,adenosine triphosphate (ATP),nanomaterials,anisotropy,cocaine,nucleic acids,toxins,DNAzyme,polarization,aflatoxin B1,ochratoxin A (OTA),tyrosinamide
更新于2025-09-10 09:29:36
-
Remote Ischemia Influences the Responsiveness of the Retina: Observations in the Rat
摘要： Remote ischemic preconditioning (RIP) has been found to be protective of heart and brain against ischemic injury. We have tested the effects of RIP on retinal function using the electroretinogram. METHODS. Ischemia remote from the retina was induced in one hindlimb, using a pressure cuff applied for between 5 and 10 minutes. A temperature probe on the footpad con?rmed blockage of the circulation. To test the impact of RIP on retinal function, we recorded the dark-adapted ?ash electroretinogram (ERG) in four groups (n ? 5 per group) of Sprague-Dawley rats (sham, 5-minute, 10-minute, and 2 3 5-minute ischemia). Heart rate, breath rate, and peripheral oxygen saturation were monitored using infrared pulse oximetry. RESULTS. RIP increased both the a- and b-waves by up to 14%, more markedly after the longer periods (10 minutes or 2 3 5 minutes) of ischemia. The effect was tested up to 30 minutes after ischemia and retested at 1 week and 1 month. RIP did not appear to accelerate the initial stages of recovery from photopigment bleach. Systemic oxygen saturation, heart rate, and respiration did not vary consistently during or after remote ischemia. CONCLUSIONS. The effect of RIP on the ERG is a novel ?nding. Possible mechanisms of this effect are discussed and related to the idea of neuroprotection and to fundamentals of the electroretinogram.
关键词： remote ischemic preconditioning,ATP-sensitive potassium channel,dark adaptation,adenosine,electroretinogram,retina
更新于2025-09-09 09:28:46