Emission fluorescence scans

Figure 10. Excitation (left) and emission (right) spectra optimized for aleurone tissue showing intensity differences between aleurone, endosperm, and pericarp tissues. The emission monochromator was set at 445 nm for excitation spectral scans and the excitation monochromator was set at 350 nm for emission spectral scans. RFI = relative fluorescence intensity. (From [29])...

Fig. 2.12. (a) Fluorescence spectrum of sennoside A on a silica gel TLC plate after spraying with hydrazine. Detection Aminco-Bowman spectrofluorimeter, with a TLC-scanning accessory. Ex = excitation, Em = emission, (b), Scan of a TLC analysis of a Sennokot tablet extract obtained with a Zeiss chromatogram scanner. Peaks 1 3 sennoside B 2 = sennoside A 3 = sennoside C. 

Figure 5. Fluorescence scans of emission following excitation of N = 4, J — 9/2 of the V = 0 level in OH in a CHk-air flame. Top (1,0) band fluorescence, emitted by molecules collisionally transferred upwards to v = 1 bottom two rotational lines in the (0,0) band, emitted by molecules in the N = = 12 level of V — 0. Both scans are on the same intensity scale.

Of the five probes evaluated only Probes 1, 3, and 5 were worth evaluating in detail, as the others had small Stokes shift (excitation wavelength, /v, minus emission wavelength, /Vln) or no detectable emission. Fluorescence behavior was measured using a Zeiss LSM 510 Laser Scanning Confocal Microscope (LSCM) and an Ocean Optics USB2000 spectrometer. 

Figure 3 Fluorescence scan of WSP1 with and without added DNA at the emission wavelength of600 nm.

Technical examination of objects coated with a protective covering derived from the sap of a shrubby tree produces information that can be used to determine the materials and methods of manufacture. This information sometimes indicates when and where the piece was made. This chapter is intended to present a brief review of the raw material urushi, and the history and study of its use. Analytical techniques have included atomic absorption spectroscopy, thin layer chromatography, differential thermal analysis, emission spectroscopy, x-ray radiography, and optical and scanning electron microscopy these methods and results are reviewed. In addition, new methods are reported, including the use of energy dispensive x-ray fluorescence, scanning photoacoustical microscopy, laser microprobe and nondestructive IR spectrophotometry. 

For normal fluorescence scanning, a high-intensity xenon continuum source or a mercury vapor hne source is used, and a cutoff Alter is placed between the plate and detector to block the exciting UV radiation and transmit the visible emitted fluorescence. For fluorescence measurement in the reversed-beam mode, a monochromatic Alter is placed between the source and plate and the monochromator between the plate and detector. In this mode, the monochromator selects the emission wavelength, rather than the excitation wavelength as in the normal mode. 

Initial fluorescence scans on epidermal strip guard cell chloroplasts in a single stomate were made using the SpectraCube 1000 system [5] after which NO treated and untreated strips were photographed (Fuji ASA/100 - color film) by an Olympus-Vanox AH-3 Fluorescent Microscope - excitation wavelength -410-490 nm, emission - 669 nm, exposure time - 18 sec. Developed color slides were subsequently scanned with a computer-linked adapted Li-Cor Spectroradiometer Model 18 00, which enabled quantitative composite fluorescence readings at 669 nm. 

For these substances a separation on RP plates (Nano SIL Cig-50, Macherey-Nagel) with the solvent methanol/water (6 4) over a distance of 6 cm was possible (47). The detection is done under a UV lamp by excitation to fluorescence. The Revalues were 0.34 and 0.45 for griseofulvin and dechlorogriseofulvin, respectively (see Fig. 6). For quantitative determinations, 250 nl of standards and samples (concentrations from 0.2 to 1.0 mg griseofulvin/ml ethyl acetate) were spotted and the separated spots excited to fluorescence at 295 nm the emission was scanned at 428 nm. 

It has been suggested that germanium may provide an alternative to Si(Li) for x-ray fluorescence scanning of the thyroid (2). If feasible, this replacement could also permit the detector system to be used for routine emission scanning of the thyroid with [ Tc] pertechnetate, due to the significantly greater efficiency of germanium. This concept... 

Patton JA, and Brill AB. 1978. Simultaneous emission and fluorescent scanning of the thyroid. J Nucl Med 19 464. 

The most widely employed optical method for the study of chemical reaction dynamics has been laser-induced fluorescence. This detection scheme is schematically illustrated in the left-hand side of figure B2.3.8. A tunable laser is scanned tlnough an electronic band system of the molecule, while the fluorescence emission is detected. This maps out an action spectrum that can be used to detemiine the relative concentrations of the various vibration-rotation levels of the molecule. 

Fluorometry and Phosphorimetry. Modem spectrofluorometers can record both fluorescence and excitation spectra. Excitation is furnished by a broad-band xenon arc lamp foUowed by a grating monochromator. The selected excitation frequency, is focused on the sample the emission is coUected at usuaUy 90° from the probe beam and passed through a second monochromator to a photomultiplier detector. Scan control of both monochromators yields either the fluorescence spectmm, ie, emission intensity as a function of wavelength X for a fixed X, or the excitation spectmm, ie, emission intensity at a fixed X as a function of X. Fluorescence and phosphorescence can be distinguished from the temporal decay of the emission. 

---