Scanner arrays

Shi Y., Simpson P.C., Scherer J.R., Wexler D., Skibola C., Smith, M.T., and Mathies R.A., Radial capillary array electrophoresis microplate and scanner for high-performance nucleic acid analysis, Anal. Chem. 71, 5354, 1999. 

Through a process called hybridization probing, the genes from the samples pair up with their complementary counterparts on the solid supports. When the hybridization step is completed, a scanner (laser beam and camera) is used to capture the fluorescence image of the array. 

Medical scanners have an array of transducers in each probe and are capable of providing thousands of measurements of the small changes in the velocity of sound as it passes through various phase changes within the body. This information is fed to computers that create a television picture of the internal tissues of the human body. 

All arrays are scanned with the exact same scanner settings. Otherwise, it can result in image data errors between samples. 

Figure 3 A third-generation CT baggage scanner typically has a conveyor belt for the bags that passes through a hole in a rotating disk that supports an X-ray source and an array of detectors. The conveyor motion direction in this drawing is into the page.

Nimblegen adopted the MAS approach to create arrays containing as many as 786,432 probe features in a 2.3-cm area on a slide. Oligonucleotides in the range of 24 to 90-mer are synthesized with good stepwise yields. In order to accommodate current scanner resolution, the densities have been reduced. Two formats covering the area of a standard slide are provided 195,000 probes (1 4) and 390,0(X) probes (1 2). A 24-mer array can be synthesized within 2 to 4 hr. The average stepwise yield is 97.5%. 

Slide-based microarray technology was first introduced by Schena etal. (1995). The processes and equipment for preparing (arrayer) and analyzing (laser scanner) microarray slides comprised a portion of Dari Shalon s thesis work at Stanford University. Polymerase chain reaction (PCR) products (cDNA probes) were attached to PLL-coated glass microscope slides. The... 

Fragmented, biotinylated RNA prepared in this manner was hybridized to the array and the signal developed using streptavidin-R-phycoerytherin. A confocal laser scanner was used for detection. The researchers estimated that they could detect two transcripts per cell based upon labeling efficiency and an estimated 4% mRNA content in total bacterial RNA. Thus, chip detection of labeled transcripts was found to be more sensitive than detection by Northern blot. Specific genes (e.g., basal levels of cinA) undetectable on Northern blots were quantifiable on the microarray. In addition, it was... 

Figure 6.19 ImmunoRCA antihuman microarray dose response for pnrified IgE. Signals from six microarray spots were averaged for each point and the background (no IgE) signal was subtracted. Inset Microarray scanner image of antihuman IgE array incubated with 1 ng/mL IgE. (From Schweitzer, B. et al., Proc. Natl. Acad. Sci. USA, 97, 10113-10119, 2000. With permission.)...

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