THE GROWTH OF ANIMAL CELLS IN BACTERIOLOGICAL MEDIA

1965 ◽  
Vol 43 (7) ◽  
pp. 933-942
Author(s):  
C. P. Kenny ◽  
H. Lees

HeLa and ascites tumor cells could be cultured in a medium of bacteriological nutrient broth plus yeast RNA. There was no growth if the RNA was omitted from the medium. The growth-promoting property of the RNA resided in a high molecular weight (mol. wt. 1–2 × 105) fraction of the RNA and not in any small sequence of nucleotides.

1975 ◽  
Vol 23 (4) ◽  
pp. 251-270 ◽  
Author(s):  
A Penttila ◽  
E M McDowell ◽  
B F Trump

The effects of fixation with glutaraldehyde (GA), formaldehyde (FA), glutaraldehyde-formaldehyde (GA-FA), flutaraldehyde-osmium tetroxide (GA-Os04) and osmium tetroxide (OsO4) on cel volume were studied in control, p-chloromercuribenzene sulfonic acid (PCMBS)-treated and hypotonically-treated Ehrlich ascites tumor cells. Among the variables investigated were concentration of the tixative agent, osmolity of the buffer, total osmolaity of the fixation solution, osmolaltity of the postfixation buffer and the time of fixation and postfixation treatment; in addition, the effects of adding calcium and high molecular weight compounds to the fixative solution were studied. When the effects of standard fixatives on control, PCMBS- and hypotonically-treated cells were compared, marked differences were apparent in the behavior of control and injured cells. Control cells retained near prefixation volume in 3% GA and 3% GA-1% OsO4, swelled in 4% FA or 1% OsO4 and phosphate buffer (tkrp), whereas tpcmbs (310 mosM KRP)- and hypotonically-treated cells (103 mos M KRP) shrank in all aldehyde fixatives but swelled in 1% OsO4. Reducing the buffer osmolality had similar effects on control and injured cells although, there were variations in degree...


1973 ◽  
Vol 51 (4) ◽  
pp. 379-389 ◽  
Author(s):  
Gerald Krystal ◽  
Peter G. Scholefield

In the partial purification of uridine kinase (ATP:uridine 5′-phosphotransferase, EC 2.7.1.48) from Ehrlich ascites tumor cells, two active fractions were obtained by chromatography on Sepharose 6B. Their molecular weights, as determined by a gel filtration and sucrose density centrifugation, were approximately 120 000 and 30 000. The larger molecular weight species was less stable on incubation at 60° and slightly less sensitive to CTP inhibition than the lower molecular weight fraction. Both fractions were stabilized against heat inactivation by ATP and CTP.The two fractions displayed similar apparent Km values for uridine and ATP, similar specificities for substrates and inhibitors, and similar divalent cation requirements.In the partial purification of uridine kinase from mouse intestine, only the larger molecular weight fraction was obtained by chromatography on Sepharose 6B.In addition, some preliminary evidence for a monomer–polymer relationship between the two molecular weight species is presented.


1970 ◽  
Vol 46 (2) ◽  
pp. 245-251 ◽  
Author(s):  
Bland S. Montenecourt ◽  
Margaret E. Langsam ◽  
Donald T. Dubin

Discrete RNA fractions sedimenting slightly slower than 18s ribosomal RNA have been found in mitochondrial preparations from both hamster (BHK-21) and mouse (L-929) cells. This RNA could be separated into two components, present in approximately equimolar amounts, by prolonged zonal centrifugation or acrylamide gel electrophoresis. The hamster components had sedimentation constants averaging 16.8 and 13.4, and molecular weights (estimated by gel electrophoresis) averaging 0.74 and 0.42 x 106 daltons. Mixed labeling experiments showed that the mouse components sedimented and electrophoresed 3–6% more slowly than the corresponding hamster components. The RNA from both cell lines resembled mitochondrial ribosomal RNA from yeast and Neurospora in being GC poor, and in addition the larger and smaller components resembled each other in base composition. These results, taken with those of other recent studies, are compatible with the idea that our high molecular weight mitochondrial RNA is ribosomal; such RNA would then constitute a uniquely small size-class of ribosomal RNA.


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