[1] Fluorescence: Basic concepts, practical aspects, and some anecdotes

Fluorescence anisotropy measurements in solution: Methods and reference materials (IUPAC Technical Report)

“…The transmission of grating monochromators or pressure cell vessel walls is particularly sensitive to the linear polarization orientation of the incoming beam, an effect that can also be very strongly wavelength dependent [10]. This differential sensitivity of the detection channel can be corrected for (at each emission wavelength, λ em ) by the G-factor, which represents the ratio of the sensitivity of the detection system for vertically and horizontally polarized light: (10) The value of G(λ em ) is best determined by exciting the fluorescent sample with horizontally polarized light [21], keeping unchanged the rest of the optical settings (slits, filters, etc.). In this way, the detection channel is illuminated by an identical amount of horizontally and vertically polarized light.…”

“…A typical instrument in L-or T-format detects an intensity, which is not proportional to the total intensity unless the so-called magic angle settings are used. Several magic angle settings for the excitation and emission polarizer combination are possible [4,10]. The most commonly encountered optical configuration uses excitation light polarized in the vertical direction.…”

“…It should be noted, however, that polystyrene cuvettes have been successfully used for 1-anilino-8-naphthalenesulfonate (ANS) depolarization studies [10,25,27]. A pernicious systematic error can be introduced using 10 × 3 or 10 × 2 mm cuvettes (internal pathlength dimensions).…”

“…The theoretical aspects underlying the emission of polarized fluorescence are presented with great detail in a number of general and specific textbooks [1][2][3][4] and journal publications. Conversely, the practical aspects of the corresponding experimental techniques, including the description of the most frequent sources of systematic errors that corrupt the measurement of polarized fluorescence intensity, are quite dispersed in the literature [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. As a consequence, we would like to present here a comprehensive discussion of spectroscopic methods used currently in the measurement of fluorescence polarization, both steady-state and time-resolved, focusing on those practices that provide accurate and reproducible values of fluorescence polarization from liquid solutions.…”

The Solution Structure and Dynamics of Full-length Human Cerebral Dopamine Neurotrophic Factor and Its Neuroprotective Role against α-Synuclein Oligomers

“…Using steady-state tryptophan intrinsic fluorescence polarization (69) and far dot blotting (70) we did not find any evidence of interaction among CDNF and neither monomeric nor oligomeric ␣-synuclein (data not shown). Notwithstanding, other possible mechanisms of action for CDNF might include: 1) binding to a transmembrane receptor, like other neurotrophic factors, activating survival pathways that surpasses the toxic effect of ␣-synuclein; 2) stimulating the cellular clearance pathways such as chaperone-mediated autophagy; and 3) inhibiting apoptosis by interaction with BAX via its Ku70-like active site (15,18).…”