Random Access Scanning
Random Access Scanning - Related Videos
02:28
Leaky Scanning
0 Views •
2020
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...
12:03
Differential Scanning Calorimetry
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2023
Source: Danielle N. Beatty and Taylor D. Sparks, Department of Materials Science and Engineering, The University of Utah, Salt Lake City, UT Differential scanning calorimetry (DSC) is an important measurement to characterize thermal properties of materials. DSC is used primarily to calculate the amount of heat stored in a material as it heats up (heat capacity) as well as the heat absorbed or released during chemical reactions or phase changes. However, measurement of this heat can also lead to...
11:14
Primer-Free Aptamer Selection Using A Random DNA Library
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Cited by 20 •
2010
SELEX protocols comprise multiple rounds of selection, each of which require regeneration of bound ligands, which in turn require fixed primer sequences flanking the random library regions. These fixed primer sequences can interfere with the selection process (false positives and negatives). Here we present a primer-free protocol.
14:37
Accessibility to Clinical Care for People who use Wheelchairs
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2023
Source: Yetsa Tuakli-Wosornu1,2, Jaideep Talwalkar1; 1Yale School of Medicine, 2University of Pittsburgh In the United States, 25% of the general population suffers from one or another type of disability. Ambulatory disabilities, or mobility impairments, represent the most common subcategory, comprising 14% of the country's populace. Different mobility-assistive devices, ranging from canes to scooters, enable increased independence and improved quality of life for those suffering from mobility...
11:41
Scanning Electron Microscopy (SEM)
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2023
Source: Laboratory of Dr. Andrew J. Steckl — University of Cincinnati A scanning electron microscope, or SEM, is a powerful microscope that uses electrons to form an image. It allows for imaging of conductive samples at magnifications that cannot be achieved using traditional microscopes. Modern light microscopes can achieve a magnification of ~1,000X, while typical SEM can reach magnifications of more than 30,000X. Because the SEM doesn’t use light to create images, the resulting pictures it...
FAQs
The microscope’s excitation beam is redirected among predefined regions of interest, allowing each selected site to receive a controlled amount of measurement time. Timing and dwell, meaning the period spent at a location, can be adjusted for the experimental design. This coordination lets researchers sample multiple neuronal structures without allocating acquisition time to positions that are not part of the investigation.
Selective sampling concentrates acquisition on structures that carry the relevant fluorescence signal instead of distributing measurements across the entire field. Because unnecessary image acquisition is reduced, the system can revisit selected somata, dendrites, or axons with controlled timing. This is particularly important when calcium dynamics or other rapid neural events change faster than conventional frame-based imaging can follow.
Conventional raster imaging measures positions across a field in a regular sequence, whereas Random Access Scanning prioritizes predefined regions of interest. The distinction is not simply spatial; it changes how acquisition time is allocated. In neuroscience, the selective approach supports rapid recordings from distributed neural structures, while frame-based imaging provides broader field coverage that may include many positions unrelated to the measurement.
A typical workflow begins by identifying relevant regions of interest, such as neuronal somata, dendrites, or axons. The microscope then directs its excitation beam among those locations, using beam-steering devices to control the sequence, timing, and dwell at each site. Fluorescence is collected from the selected structures, producing time-resolved measurements focused on the neural activity under study.
The approach can target neuronal somata, dendrites, and axons, as well as distributed regions selected for their relevance to a neural process. Measurements are based on fluorescence signals collected at those sites. In the stated neuroscience applications, this supports examination of calcium dynamics, neuronal signaling, and coordination of activity across neural populations.
Random Access Scanning is useful when researchers need high-temporal-resolution information from multiple, spatially distributed neural structures. It can support studies of calcium dynamics, rapid neuronal signaling, and network coordination, especially when activity changes too quickly for efficient frame-based acquisition. By focusing measurements on relevant regions, the technique connects signals from individual structures with broader patterns of neural population activity.