Michelson

Figure Bl.2.6. Schematic representation of a Michelson interferometer. From Griffiths P R and de Flaseth J A 1986 Fourier transfonn infrared spectroscopy Chemical Analysis ed P J Hiving and J D Winefordner (New York Wiley). Reprinted by pemiission of Jolm Wiley and Sons Inc.

A typical noisy light based CRS experiment involves the splitting of a noisy beam (short autocorrelation time, broadband) into identical twin beams, B and B, tlnough the use of a Michelson interferometer. One ami of the interferometer is computer controlled to introduce a relative delay, x, between B and B. The twin beams exit the interferometer and are joined by a narrowband field, M, to produce the CRS-type third order polarization in the sample ([Pg.1209]

Figure B2.1.2 Modified Michelson interferometer for non-collinear intensity autocorrelation. Symbols used rl, r2, retroreflecting mirror pair mounted on a translation stage bs, beamsplitter x, nonlinear crystal pint, photomultiplier Pibe.

Michelson, A M. 1963, The Chemistry of Nucleosides and Nucleotides, Academic Press New York London... 

The most important component of an FTIR spectrometer is an interferometer based on the original design by Michelson in 1891, as shown in Figure 3.11. 

In an industrial-design FTIR spectrometer, a modified form of the G enzel interferometer is utilized.A geometric displacement of the moving mirrors by one unit produces four units of optical path difference (compared with two units of optical difference for a Michelson type interferometer). The modified Genzel design reduces the time required to scan a spectrum and further reduces the noise effects asstxiated with the longer mirror translation of most interferometers. 

Fluor Daniel Inc. 3333 Michelson Drive, Irvine, CA 92730 Phone (714) 975-5854... 

On the basis of the luciferin-luciferase reaction discovered by Dubois (1887), Michelson, Henry and their associates studied the biochemistry of the Pholas bioluminescence for several years beginning in 1970 (Michelson, 1978). They isolated, purified, and characterized the luciferin and the luciferase, and published about a dozen papers in which the luciferin isolated was referred to as Pholas luciferin. Since the luciferin is clearly a protein, later authors called it pholasin following the traditional way of naming a photoprotein... 

Assay of pholasin. Two different methods have been used. In the first method, light intensity or total light emission is measured when a standard solution of luciferase is added to a pholasin sample (Henry et al., 1970). In the second method, total light emission is measured when 1 ml of a degassed solution of 0.3 mM FeSC>4 is injected into 2 ml of 0.15 M phosphate buffer, pH 7.0, containing a pholasin sample and 0.75 M NaCl (Michelson, 1978). The luminescence reaction is complete within 2 or 3 min. 

Purification of Pholas luciferase (Michelson, 1978). Acetone powder of the light organs is extracted with 10 mM Tris-HCl buffer, pH 7.5, and the luciferase extracted is chromatographed on a column of DEAE Sephadex A-50 (elution by NaCl gradient from 0.1 M to 0.6 M). Two peaks of proteins are eluted, first luciferase, followed by a stable complex of luciferase and inactivated pholasin. The fractions of each peak are combined, and centrifuged in 40% cesium chloride... 

Assayed by the luminol chemiluminescence method (Puget and Michelson, 1974). One unit corresponds to 0.35 unit of the cytochrome c method (McCord and Fridvich, 1969). 

Henry, J. P., and Michelson, A. M. (1970). Studies in bioluminescence. IV. Properties of luciferin from Pholas dactylus. Biochim. Biophys. Acta 205 451-458. 

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