Endogenous fluorescence

Laiho, L. H., Pelet, S., Hacewicz, T. M., Kaplan, P. D., and So, P. T. C. 2005. Two-photon 3-D mapping of ex vivo human skin endogenous fluorescence species based on fluorescence emission spectra. J. Biomed. Opt. 10 1-10. 

Solid-phase extraction is routinely used to clean up extracts prior to quantitation (19,42,70, 80-82). Alternatively, endogenous fluorescent artifacts in food samples can be eliminated by oxidation with potassium permanganate/hydrogen peroxide/sodium metabisulphite. Benzyl alcohol has been used to extract riboflavin selectively without the coenzymes, permitting the determination of free riboflavin. 

Skala MC, Squirrell JM, Vrotsos KM, Eickhoff VC, Gendron-Fitzpatrick A, Eliceiri KW, Ramanujam N (2005) Multiphoton microscopy of endogenous fluorescence differentiates normal, precancerous, and cancerous squamous epithelial tissues. Cancer Res 65 1180—1186... 

Schwertner has isolated albumin-associated fluorescent ligands that have an emission maximum of 415 nm (S17). The fluorescent species is very water soluble and can be removed by charcoal (S16). A positive correlation was found between fluorescence and serum creatinine in patients maintained on conservative treatment (D15), but not in patients already on hemodialysis (S16). Interestingly, the serum of patients with acute renal failure does not emit this fluorescence, a fact that has been proposed as a differential criterion between acute and chronic renal failure (V2). Mabuchi et al. have used HPLC to demonstrate numerous endogenous fluorescent substances at excitation (Ex) 322 nm/emission (Em) 415 nm in chronic renal failure and concluded that some of these fluorescent peaks probably represented peptidic substances, but did not identify any of them (M7). 

Numerous endogenous fluorescent substances are present in uremic sera and urine HPLC with fluorescence detection of uremic serum and urine passed through Centriflo CF 25 filter guanidine compound and amino acids removed... 

Subsequent studies by the same group (W7) have shown that the increased endogenous fluorescence in patients with chronic renal failure is due to the unconjugated pteridine, xanthopterin (2-amino-4,6-pteridinedione, 179 Da see Table 4 and Figs. 10 and 11) (B23, Dll, L15, Pll). Unlike the conjugated pteridines (folates), the function of many of the unconjugated pteridines (pterins) has yet to be elucidated (U2, Z3). So far only biopterin has been shown to have a defined role, being a cofactor in the hydroxylation of several aromatic amino acids involved in the formation of neuronal hormones such as catecholamines and serotonin. 

M7. Mabuchi, H., and Nakahashi, H., Liquid-chromatographic profiling of endogenous fluorescent substances in sera and urine of uremic and normal subjects. Clin. Chem. (Winston-Salem, N.C.) 29, 675-677 (1983). 

In spite of the generally low luminescence quantum yields, NIR luminescent lanthanide complexes, and particularly those of Yb ", are of interest for bioanaly-tical applications, since (1) their luminescence will be less hindered by endogenic fluorescence from biological material, (2) antenna chromophores with high extinction coefficients may be incorporated into the complexes that compensate for the low quantum yield and (3) powerful visible and NIR excitation sources can be used. In the following, we will outline the work done on the development of NIR luminescent lanthanide complexes. 

Next, total rat hver proteins were examined for the presence of linkages characteristic of ADP-ribosyl-cysteine. Trichloroacetic acid insoluble extracts of hver tissue were treated to remove non-covalently bound ADP-ribose and subsequently treated with mercuric ion and analyzed for ADP-ribose. Fig. 2 shows such an analysis along with control experiments. Panel A shows that analysis of an extract treated with mercuric ion exhibited a fluorescent peak that migrated at the expected elution position of etheno-ADP-ribose, the fluorescent derivative used for quantitative determination of ADP-ribose. Panel B shows the analysis in which mercuric ion was omitted from a parahel sample of hver extract. Panel C shows the result obtained when chloroacetaldehyde, which is required for the formation of the fluorescent derivative of ADP-ribose, was omitted. This control rules out the possibility of endogenously fluorescent compounds present in the ceh extract that were released by mercuric ion. Panel D shows that a small amoimt of authentic etheno-ADP-ribose added to extracts prepared as in... 

Beliveau R, Moroney JV and McCarty RE (1982) Endogenous fluorescence of coupling factor 1 from spinach chloroplasts. Arch. Biochem. Biophys. 

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