Culture-based labelling

Latter et al have recently published the results of a study in which cells growing in culture were labelled with 20 radioactive amino acids, each in a different experiment, and analyzed by 2D6EL (S4). The resulting autoradiographs were studied with an image analysis system so that amino acid compositional data could be extracted. This information was then compared to the amino acid composition data resident in two large data bases, using computerized search methods. Out of the 122 spots studied in this manner, tentative identifications could be made on 17 of them based on the amino acid composition alone. 

Microarray detection methods In the early days of protein microarray analysis, mostly radioisotope-based labeling was applied, especially for phosphorylated proteins [99]. Later, stable isotope-coded amino acids (SILAC) proved useful in in vivo incorporation to cell cultures [100]. Both methods were very sensitive, requiring only minute sample amounts to reveal protein expression differences [101]. The use of an enhanced chemiluminescence (ECL) technique using X-ray film exposure or a phosphor imager instrument was. 

Wines may be imported for reasons at either of two extremes because they are relatively inexpensive, or because they are in high demand, and thus command a higher price. Those exported from the United States tend to be the former, and those imported, the latter, based on the data shown in Table 5. There is some market, even in countries that are overproducing wine, for wines with exotic labels. This tendency illustrates another way in which wines differ from other products. Information on and cuisine from foreign countries associated with their wines serve as the vehicles for a form of a cultural exchange, besides the stricdy commercial one. 

Quantitative determination of the absolute distance from the surface to a labeled cell membrane at a cell/substrate contact region can be based on the variation of F(d) with 0.(1O6) This effort is challenging because corrections have to be made for 0-dependent reflection and transmission through four stratified layers (glass, culture medium, membrane, and cytoplasm), all with different refractive indices. For 3T3 cells, Lanni et a//1065 derived a plasma membrane/substrate spacing of 49 nm for focal contacts and 69 nm for close contacts elsewhere. They were also able to calculate an approximate refractive index for the cytoplasm of 1.358 to 1.374. 

Incubation of Pseudomonas putida with anthracene-labeled carbon-base ferrichrome analog Fe(lll) complex 173 resulted in cellular iron uptake and the appearance of anthracene fluorescence in the culture medium identical to the Fe-ferrichrome uptake. Incubation with the alanyl analog 174 failed to show any significant iron uptake or fiuorescence. This is consistent with the tests described above on the unlabeled analogs. Remarkably, other strains such as Pseudomonas fluorescens S680 or WCS3742 also did not show any iron uptake or culture fluorescence. 

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