Trypsin sensitivity of mammalian cells grown in a serum-free medium

In Vitro ◽  
1971 ◽  
Vol 6 (4) ◽  
pp. 266-268 ◽  
Author(s):  
Robert W. Pumper ◽  
Peter Fagan ◽  
William G. Taylor
Keyword(s):  
Mammalian Cells ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free

Interferon production by mammalian cells grown in a serum-free medium

In Vitro ◽  
1979 ◽  
Vol 15 (5) ◽  
pp. 388-392 ◽  
Author(s):  
Robert W. Pumper ◽  
Leonard Molander
Keyword(s):  
Mammalian Cells ◽  
Interferon Production ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free

Lipid metabolism in cultured cells. III. Cholesterol excretion process

1964 ◽  
Vol 207 (6) ◽  
pp. 1221-1225 ◽  
Author(s):  
J. Martyn Bailey
Keyword(s):  
Tissue Culture ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Rabbit Aorta ◽  
Rabbit Serum ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Cholesterol Excretion

Mammalian cells grown in tissue culture have been shown previously to take up considerable quantities of cholesterol from the growth medium. When cells grown on cholesterol-C14 supplemented medium were transferred to unlabeled medium containing serum, excretion of cholesterol into the outside medium took place. When cell cholesterol was labeled by intracellular synthesis from mevalonate-C14 precursor, it also was excreted readily into the serum medium. This excretion did not take place in serum-free medium and was found to be stimulated by a nondialyzable, thermolabile component of human serum. Horse, chicken, calf, and rabbit serum also showed stimulation ability. The process of cholesterol excretion appears to be of general occurrence. It was found in both strains of cultured cells examined (mouse fibroblasts and lymphoblasts) and also in strips of rabbit aorta incubated in vitro.

scholarly journals MOLECULAR GROWTH REQUIREMENTS OF SINGLE MAMMALIAN CELLS

1959 ◽  
Vol 109 (6) ◽  
pp. 649-660 ◽  
Author(s):  
Harold W. Fisher ◽  
Theodore T. Puck ◽  
Gordon Sato
Keyword(s):  
Cell Growth ◽  
Hela Cells ◽  
Generation Time ◽  
Mammalian Cells ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Growth Requirements ◽  
Cent Efficiency ◽  
Dialyzed Serum

Two purified serum protein fractions, fetuin and serum albumin, will replace whole or dialyzed serum in supporting the growth of single S3 HeLa cells in an otherwise chemically defined nutrient solution. In the serum-free medium, single S3 cells will form macroscopic colonies with essentially 100 per cent efficiency. The generation time of S3 cells in the serum-free medium is approximately 50 per cent greater than that observed in an optimal, serum-containing medium. All components of the serum-free medium are available commercially, except fetuin, which can easily be prepared in substantial quantities. The problem of the purity of the protein preparations and of their possible roles in promoting cell growth is discussed.

Egg yolk lipoprotein, a new supplement for the growth of mammalian cells in serum-free medium

1988 ◽  
Vol 1 (2) ◽  
pp. 159-169 ◽  
Author(s):  
Hiroki Murakami ◽  
Yuichi Okazaki ◽  
Koji Yamada ◽  
Hirohisa Omura
Keyword(s):  
Mammalian Cells ◽  
Egg Yolk ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Lipoprotein A

Exogeneous factors are not necessary in attachment, spreading and polarization of hela cells

1978 ◽  
Vol 36 (2) ◽  
pp. 310-311
Author(s):  
W. Liebrich
Keyword(s):  
Hela Cells ◽  
Calf Serum ◽  
Glass Tube ◽  
Serum Free Medium ◽  
Nacl Solution ◽  
Free Medium ◽  
Minimum Essential Medium ◽  
Serum Free ◽  
All Solutions ◽  
Glass Support

HeLa cells were grown for 2-3 days in EAGLE'S minimum essential medium with 10% calf serum (S-MEM; Seromed, München) and then incubated for 24 hours in serum free medium (MEM). After detaching the cells with a solution of 0. 14 % EDTA and 0. 07 % trypsin (Difco, 1 : 250) they were suspended in various solutions (S-MEM = control, MEM, buffered salt solutions with or without Me++ions, 0. 9 % NaCl solution) and allowed to settle on glass tube slips (Leighton-tubes). After 5, 10, 15, 20, 25, 30, 1 45, 60 minutes 2, 3, 4, 5 hours cells were prepared for scanning electron microscopy as described by Paweletz and Schroeter. The preparations were examined in a Jeol SEM (JSM-U3) at 25 KV without tilting.The suspended spherical HeLa cells are able to adhere to the glass support in all solutions. The rate of attachment, however, is faster in solutions without serum than in the control. The latter is in agreement with the findings of other authors.

Hemoglobin Enhances the Binding of Bacterial Endotoxin to Human Endothelial Cells

1996 ◽  
Vol 76 (02) ◽  
pp. 258-262 ◽  
Author(s):  
Robert I Roth
Keyword(s):  
Endothelial Cells ◽  
Binding Protein ◽  
Bacterial Endotoxin ◽  
Dependent Manner ◽  
Serum Free Medium ◽  
Free Medium ◽  
Human Endothelial Cells ◽  
Serum Factors ◽  
Serum Free ◽  
Lps Binding

SummaryHuman endothelial cells, when incubated with bacterial endotoxin (lipopolysaccharide, LPS), modify their surface in association with prominent production of procoagulant tissue factor (TF) activity. This deleterious biological effect of LPS has been shown previously to be enhanced approximately 10-fold by the presence of hemoglobin (Hb), a recently recognized LPS binding protein that causes disaggregation of LPS and increases the biological activity of LPS in a number of in vitro assays. The present study was performed to test the hypothesis that Hb enhances the LPS-induced procoagulant activity of human umbilical vein endothelial cells (HUVEC) by increasing LPS binding to the cells. The binding of 3H-LPS to HUVEC was determined in the absence or presence of Hb or two other known LPS-binding proteins, human serum albumin (HSA) and IgG. LPS binding was substantially increased in the presence of Hb, in a Hb concentration-dependent manner, but was not increased by HSA or IgG. Hb enhancement of LPS binding was observed in serum-free medium, indicating that there was no additional requirement for any of the serum factors known to participate in the interaction of LPS with cells (e.g., lipopolysaccharide (LPS)-binding protein (LBP) and soluble CD14 (sCD14)). Hb enhancement of LPS binding also was observed in the more physiologic condition of 100% plasma. LPS-induced TF activity was stimulated by Hb, but not by HSA or IgG. In serum-free medium, TF activity was not stimulated under any of the conditions tested. Ultrafiltration of LPS was dramatically increased after incubation with Hb but not with HSA or IgG, suggesting that LPS disaggregation by Hb was responsible for the enhanced binding of LPS to HUVEC and the subsequent stimulation of TF activity.

THE INFLUENCE OF SERUM ON THE UPTAKE, CONVERSION AND ACTION OF DIHYDROTESTOSTERONE IN RAT PROSTATE GLANDS IN ORGAN CULTURE

1975 ◽  
Vol 64 (2) ◽  
pp. 289-297 ◽  
Author(s):  
ILSE LASNITZKI ◽  
HILARY R. FRANKLIN
Keyword(s):  
Organ Culture ◽  
Horse Serum ◽  
Target Tissue ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Human Pregnancy ◽  
Human Male ◽  
Columnar Cells

SUMMARY The influence of serum on the uptake, conversion and action of dihydrotestosterone in relation to the sex steroid binding protein, TeBG, has been investigated in rat ventral prostates in organ culture. The organs were incubated with [1,2-3H]dihydrotestosterone in: (1) serum-free medium, (2) horse serum, foetal and newborn bovine serum or (3) human male and human pregnancy serum. With all sera the uptake of dihydrotestosterone fell with rising serum concentration, at first steeply and then more gradually. At the same concentration, the uptake was significantly lower in explants incubated with human pregnancy serum than in those kept with human male serum. The conversion of dihydrotestosterone to androstanediol followed the same pattern and less androstanediol was formed in the presence of pregnancy serum. Since pregnancy serum contains higher amounts of TeBG than male serum, the lowered uptake suggests that only the free hormone was available to the target organ. Addition of unlabelled dihydrotestosterone resulted in a higher uptake than that measured in explants incubated with the labelled steroid only. The effect of the human sera on uptake and conversion was correlated with the androgenic activity of dihydrotestosterone applied at physiological concentrations and expressed as the percentage of secretory columnar cells present. The degree of maintenance closely corresponded to the uptake of the hormone. In serum-free medium, the number of columnar cells approached the values found in vivo, with male serum their number, though reduced, was still substantial, with pregnancy serum it was extremely low. It is concluded that the amounts of TeBG present in serum regulate the supply of the hormone to the target tissue and thus control its biological action.

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