Insect cells: Colony formation and cloning in agar medium

In Vitro ◽  
1974 ◽  
Vol 10 (1-2) ◽  
pp. 1-5 ◽  
Author(s):  
Arthur H. McIntosh ◽  
Carol Rechtoris
Keyword(s):  
Colony Formation ◽  
Insect Cells ◽  
Agar Medium

On the relation of colony variants to the time dependency of colony formation during adaptive mutation of Escherichia coli FC40

1997 ◽  
Vol 43 (9) ◽  
pp. 884-886 ◽  
Author(s):  
Patricia R. MacLeod ◽  
Robert A. MacLeod
Keyword(s):  
Escherichia Coli ◽  
Carbon Source ◽  
Pure Culture ◽  
Colony Formation ◽  
Agar Medium ◽  
Selective Medium ◽  
Adaptive Mutation ◽  
Time Dependency ◽  
Colony Type ◽  
Selective Agar

When Escherichia coli FC40 formed adaptive Lac+ revenants on a selective agar medium containing lactose as the carbon source, the colonies which accumulated over several days were of two readily distinguishable types. Colonies of both types appeared both early and late on the plates. Cells of colonies that appeared early and late on the plates, irrespective of the type, when grown in liquid medium and replated, all formed colonies on the selective medium within 48 h. Cells of each colony type gave rise to colonies of both types and attempts to isolate cells of each type in pure culture were unsuccessful. It was concluded that the presence of two colony types in the cultures plated did not contribute to the observed time dependency of colony formation during adaptive mutation. The proportions of the two colony types arising from cultures of the Lac+ revertants varied from culture to culture.Key words: Escherichia coli FC40, variants, adaptive mutation, colony accumulation.

scholarly journals Caprylate-thallous agar medium for selectively isolating Serratia and its utility in the clinical laboratory

1976 ◽  
Vol 4 (3) ◽  
pp. 270-276
Author(s):  
M P Starr ◽  
P A Grimont ◽  
F Grimont ◽  
P B Starr
Keyword(s):  
Colony Formation ◽  
Octanoic Acid ◽  
High Efficiency ◽  
Clinical Laboratory ◽  
Agar Medium ◽  
Selective Medium ◽  
Bacterial Strains ◽  
Low Efficiency ◽  
Hospital Acquired ◽  
Very High

A defined agar medium (hereinafter designated caprylate-thallous [CT5 agar) containing 0.01% yeast extract, 0.1% caprylic (n-octanoic) acid, and 0.025% thallous sulfate is highly selective for all Serratia species and effectively discriminates against most non-Serratia strains likely to be in the same habitats. The selectivity of CT agar is demonstrated by the very high efficiency of colony formation (mean, 80.7% of that on a nonselective complex medium) on CT agar by known Serratia strains and the very low efficiency of colony formation (close to zero) on CT agar by bacterial strains known not to be Serratia. The utility of this medium in actual clinical laboratory practice is demonstrated by the more rapid and higher recovery of Serratia on this selective medium as compared to conventional procedures of in-tandem runs of 513 consecutive urine, feces, and sputum specimens. Pigmented and nonpigmented Serratia strains deliberately added to fecal specimens can be selectively and quantitatively recovered on CT agar. CT agar compares favorably with, or in some cases is an improvement over, other selective media which have been recommended for isolating Serratia. This selective CT agar medium could be quite useful in ecological surveys, especially those related to hospital-acquired infections.

Anaerobic incubation enhances the colony formation of a polA recB strain of Escherichia coli K-12

1982 ◽  
Vol 152 (1) ◽  
pp. 208-214
Author(s):  
M Morimyo
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Colony Formation ◽  
Superoxide Radical ◽  
Agar Medium ◽  
Oxygen Toxicity ◽  
Coli Strain ◽  
Permissive Temperature ◽  
Anaerobic Incubation ◽  
K 12

Escherichia coli strain E247 (polA1 recB21) has reduced colony formation (even at the permissive temperature of 30 degrees C) because of a poor suppressor mutation (sup-126). The colony formation was enhanced in the absence of oxygen about 3-fold at 30 degrees C and 10(6)-fold at 43 degrees C, suggesting that a polA recB strain was inviable due to oxygen toxicity. Colony formation was also increased by incubation in an agar medium containing the reducing agent thioglycolate and incubation in the presence of chloroform-killed Saccharomyces cerevisiae pet+ cells, but not pet cells. Since the E247 strain viability was inversely dependent on the oxygen pressure and since the strain was more sensitive to superoxide radical than either the polA or the recB mutant, it seems likely that the polA and recB genes play a role in repairing DNA damage during respiration.

scholarly journals Human interferon-inducible protein 10: expression and purification of recombinant protein demonstrate inhibition of early human hematopoietic progenitors.

1993 ◽  
Vol 178 (3) ◽  
pp. 1127-1132 ◽  
Author(s):  
A H Sarris ◽  
H E Broxmeyer ◽  
U Wirthmueller ◽  
N Karasavvas ◽  
S Cooper ◽  
...  
Keyword(s):  
Colony Formation ◽  
Insect Cells ◽  
Signal Sequence ◽  
Sodium Dodecyl ◽  
Human Interferon ◽  
Hematopoietic Progenitors ◽  
Inducible Protein ◽  
Early Human ◽  
Interferon Inducible Protein

Human interferon-inducible protein 10 (IP-10), a member of the family of the small secreted proteins called intercrine cytokines or chemokines, is secreted by interferon gamma-stimulated T cells, monocytes, endothelial cells, and keratinocytes. We have begun to explore the biological properties of IP-10 by cloning and overexpression in baculovirus and in bacterial protein expression systems. A 9.9-kD protein was secreted by infected insect cells, which on sodium dodecyl sulfate-polyacrilamide gel electrophoresis comigrated with keratinocyte IP-10 and with f(22-98), a bacterial recombinant fragment lacking the signal sequence but containing all other residues of IP-10. All three reacted with antibodies recognizing residues 10-98 (alpha IP-10) and 77-98 of IP-10 (alpha 22), demonstrating that it is secreted by keratinocytes and insect cells after removal of the signal sequence but without proteolysis of the COOH-terminal end. Purified rIP-10 suppresses in vitro colony formation by early human bone marrow progenitor cells which need r-steel factor (rSLF) and rGM-CSF or rSLF and r-erythropoeitin (rEPO). The inhibition is dose dependent, is complete at concentrations > or = 50 ng/ml, is prevented by preincubation of rIP-10 with alpha IP-10, but not by alpha 22, and is seen with highly purified CD34+ cells, suggesting direct effect of rIP-10 on the progenitors. Combination of rIP-10 and other chemokines at inactive concentrations inhibited colony formation in a synergistic manner. rIP-10 did not affect colony formation in the absence of any growth factors or in the presence of rEPO or rGM-CSF but in absence of rSLF. The effects of IP-10 may be relevant to normal marrow function and might be harnessed to protect human hematopoietic progenitors from the cytotoxic effects of chemotherapy.

A Flooded Plate Loop Count Procedure1

1980 ◽  
Vol 43 (7) ◽  
pp. 534-535 ◽  
Author(s):  
R. L. OLSEN ◽  
G. H. RICHARDSON
Keyword(s):  
Correlation Coefficient ◽  
Conventional Method ◽  
Colony Formation ◽  
Agar Medium ◽  
Raw Milk ◽  
Statistical Characteristics ◽  
Milk Samples ◽  
Standard Procedures ◽  
Conventional Plate ◽  
Petri Plate

A modification of the plate loop count procedure for milk samples is described which incorporates use of a 0.5-ml diluent loop-rinse onto pre-dried agar medium in a 100-mm petri plate. The sample is distributed using a glass spreader, the plate is dried and incubated using standard procedures. Colony formation was more uniform than with the conventional method. The method did not appear to significantly change the statistical characteristics of the plate loop count on raw milk samples. A correlation coefficient of .91 was obtained between the flooded and the conventional plate loop count.

ANTIMICROBIAL ACTIVITIES OF METHANOL EXTRACT FROM UNIDENTIFIED SPONGE ASSOCIATED BACTERIA IN LEMUKUTAN ISLAND, KALIMANTAN BARAT

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Agar Medium ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Associated Bacteria ◽  
Minimum Inhibitory Concentrations ◽  
Sponge Associated Bacteria

<p>The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity.</p> <p>Keywords:Antimicrobial,Sponges associated bacteria,MICs</p>

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