Slide-sampling, arrangement

Figure 6 Sample arrangement for impedance measurements. Note the fused silica cover slides (0.1 mm) inserted between the electrodes and the sample...

Tissue microarray (TMA) TMA technology permits to arrange hundreds or thousands of tissue cores (probes), such as clinical biopsies or tumor samples, on a single slide, and then to analyze by a single immuno-staining or in situ hybridization reaction. 

Very fine droplets tend to follow the streamlines. To account for this fact, any possible disturbance of the sampling slides to the flow field must be minimized to prevent the fine droplets escaping from the slides. For this purpose, the number and positions of the sampling slides in each run are arranged according to the moving tendency of the droplets. 

Fig. 4.8 Arrangement for surveying a variety of potential solvents for crystallization. A single small crystal is placed on a microscope cover slip. (It may be helpful to mark the location of the crystal by circling it with a felt tipped pen.) The cover slip is then inverted on a short ( 4-6 mm) piece of Tygon tubing mounted on a microscope slide. A few drops of a trial solvent are placed on the side around the periphery of the tubing. They will seep into the space inside the tubing and evaporate, filling it with vapours that may or may not dissolve the crystal. Recrystallization of the sample may be followed on the microscope, and the same sample may be reused many times without loss of material, a Cover slip with crystal in a marked circle, b Microscope slide with a slice of tubing and the coverslip with the crystal (whose size has been exaggerated for clarity).

Figure 17.14 Transmission of excitation light and fluorescence emission from Cy-5 from a periodic arrangement of 200nm diameter nanoapertures in 70nm thick gold film, with spacing of 1 Om. In these measurements, the sample angle was varied with respect to the incident light, while detection occurred from the backside in a direction collinear with the incident light. Fluorescence from a disordered array is also plotted for reference. Fluorescence is normalized to a quartz slide with the same monolayer, and corrected for fill fraction.

In general, an array is an orderiy and systematic arrangement of samples. In the case of a DNA array, these are large numbers of DNA molecules or oligonucleotides which are immobilised onto a substrate like a glass slide or a nylon membrane in the form of spots. 

Fig. 5.22. A DNA array is an orderly arrangement of immobilised oligonucleotides on a glass slide, each grey spot represents a different oligonucletide. When reacted with labelled DNA samples, they hybridise with only certain spots on the array, i.e. those containing a matching oligonucleotide sequence. This results in a characteristic pattern, a fingerprint, of coloured and uncoloured spots.

A third, usually more expensive, system has multiple detectors to count multiple samples simultaneously. Configurations available commercially are modular with groups of four detectors arranged over a slide-out drawer. Modules can be added for 8,16, or even 64 detectors. This counting system is useful for low-level samples that require long counting time (i.e., 24-96 h). A high sample load can justify the cost. 

In the given arrangement [24], the power-limited and adjusted dye laser beam falls through the quartz cuvettes with reference and sample solutions positioned on the photoacoustic cell. The two photoacoustic signals are amplified in parallel and electronically filtered with respect to low-frequency interference (AM 502, Tektronix). The amplified and filtered signals are then feed into two 165-segment boxcar slide-in modules and are subtracted from one another by the 162-regment boxcar base unit (EG + G, Princeton Applied Researdi). 

Miniaturized, multiplexed, solid-phase immunoassays were developed in the 1980s using protein microdots spotted manually onto nitrocellulose sheets and other solid supports. It was shown quite clearly that this multianalyte immunoassay format was far more sensitive than standard immunoassays carried out in microtiter dishes because the sample volumes were so much smaller. Over the last few years, these devices have evolved into protein biochips, in which microdots of antibodies or protein analytes are arranged in a dense miniature grid on a solid support such as a microscope slide. Two types of... 

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