Culture labelling

Figure 7. Higher magnification of generative hyphal walls from N-limited nutrient agar grown cultures labeled for lignin-peroxidase. Double layer of label on both margins of the hyphal wall. Magnification x 11,000.

In another set of experiments, Schlesinger and Anderson (44) showed that the isozymes are formed in vivo by alteration of the dimer. Using an E. coli mutant that makes an altered subunit, which will only dimerize (in vitro or in vivo) in the presence of phosphate or zinc, they found that the monomers produced by the cell growing in the absence of phosphate and zinc produced only one electrophoretic form when the monomer was converted to the dimer in vitro. However, if the medium is made 2 vaM in phosphate and 10 /iM in zinc, in the exponential phase of growth, three isozymes are formed. Additional support for the conclusion that isozymes are made by alteration of the dimer comes from the fact that independent of when 14C-labeled amino acids are added to the growing culture, label appears first in isozyme I. It thus appears that a mechanism is available in the periplasmic space for the conversion of isozyme I to the other isozymes. 

Autoradiography of contaminated cultures labelled with tritiated thymidine shows grains over the whole cell rather than localised to the nucleus. This is a result of degradation of the thymidine to thymine followed by incorporation into mycoplasma DNA and other cell constituents. 

Sensitive, semi-quantitative Sensitive, quantitative High resolution In vivo or in vitro labeling No labeling necessary Bidifferential expression Small sample size Detects PTMs Sensitive, quantitative In vivo or in vitro labeling 4 stable isotope labels Detects PTMs Sensitive, quantitative Cell culture labeling Bidifferential expression Detects PTMs... 

In diatoms, it is generally possible to demonstrate an absolute zinc requirement, but above that threshold, addition of zinc, cobalt, or cadmium to the cultures are equally effective at promoting fast growth. This is illustrated for zinc and cadmium in Figure 19 which also shows that the growth rate can be accelerated by increasing the Pco of Ihe medium. Native protein gels from cultures labeled... 

Bland, Lucy, and Laura Doan (eds.). Sexology in Culture Labeling Bodies and Desires (Chicago University of Chicago Press, 1998)... 

Fig. 9. Molecular weight analysis of muscle cell DNA by alkaline sucrose gradients, 27 h cultures labelled with thymidine 44, 53, 66, 75 and 92 h cultures labelled with [" H] thymidine. [" H], "C]...

Fig. 11. DNA strand-breaks in differentiating muscle cells. 20 h culture labelled with ( C] thymidine 30, 42, 56 or 90 h cultures labelled with [ H] thymidine. Q ( H) [ CJ. Analysis was by the alkaline unwinding technique...

Fig. 18. Chromatography of T2-specific RNA on a methylated albumin column (Spiegelman, 1963). Legend Chi represents chloramphenicol H -U, tritium-labeled uridine. C -U, uridine labeled with C. Shaded rectangles denote periods of administration of label. Curves of optical density indicate the presence of preformed stable cell components (4S, 16S, 23S), located in the order as shown from left to right, a) Mixture of two RNA samples rf-labeled RNA obtained from culture labeled between 13 and 15 min b) control mixture labeled with both isotopes at the same period I and I ) radioactivity (H andC respectively) II) absorption.

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