Survival ofEscherichia coli after storage in various frozen menstrua

Kocka, Frank E.; Bretz, W H

doi:10.1007/bf02219117

Cited by 6 publications

(4 citation statements)

References 27 publications

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“…Bacterial recombinants are currently preserved by freezing [27][28][29] and techniques for the long-term preservation of bacterial cultures have been devised, 27,30-33 including stab culture 34 and lyophilization. 35,36 However, viability may decrease with prolonged storage.…”

Section: Discussionmentioning

confidence: 99%

DNA Shuttling Between Plasmid Vectors and a Genome Vector: Systematic Conversion and Preservation of DNA Libraries Using the Bacillus subtilis Genome (BGM) Vector

Kaneko

Akioka

Tsuge

et al. 2005

Journal of Molecular Biology

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Section: Discussionmentioning

confidence: 99%

DNA Shuttling Between Plasmid Vectors and a Genome Vector: Systematic Conversion and Preservation of DNA Libraries Using the Bacillus subtilis Genome (BGM) Vector

Kaneko

Akioka

Tsuge

et al. 2005

Journal of Molecular Biology

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“…Furthermore the cells were frozen in phosphate maceration buffer. It has been shown that survival of bacteria in frozen buffer is lower than in distilled water (Kocka & Bretz, 1969). This is probably due to a change in pH since salts are excluded from the forming ice and concentrated.…”

Section: Discussionmentioning

confidence: 99%

“…With Escherichia coli, 10% glycerol or 10% dimethyl sulphoxide in the freezing buffer are very protective, giving a survival of over 90% (Kocka & Bretz, 1969). Moreover, rapid freezing, e.g.…”

Section: Discussionmentioning

confidence: 99%

Interpretation of the EC method for the detection of latent Corynebacterium sepedonicum infections in potato¹

Janse¹,

Vaerenbergh²

1987

EPPO Bulletin

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The EC mcthod for the detection of latent ring-rot infections (Corynebacterium sepedonicum) consists essentially of an indirect immunofluorescence test and a pathogenicity test on eggplant (EP). When interpreting the results of this method, care should be taken that: (a) eggplants iire grown at 2 1 "C. At 28-29°C the detection level ofthe EP was increased 10'to lo3fold to lo5 to lo6 cells m1-I and latent infections (which may go unnoticed) occurred with lo4 to lo5 cells nil-'; (b) reisolations are made from symptomless eggplants grown at the optimum temperatuie (21°C) as latent infections can also occur in these plants at concentrations of lo2 to 10' cells inl-'; (c) potato tuber extracts are tested without freezing or stored freeze-dried or in a proper protective agent. Freezing at -20°C in maceration buffer of cells of C. sepedonicutii and Pseudomonas solanacearum (the latter was included for comparison) reduced their numbers by 90-98"/0 after one day. This could easily cause viable cell numbers to drop below the detection level of the pathogenicity test.

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“…FREEZING TECHNIQUES Subcultured gonococci were suspended in 1% proteose peptone containing different concentrations of either glycerol or dimethylsulphoxide (Kocka and Bretz, 1969) as protective agents. Duplicate 0-1 ml volumes containing about 107 gonococci were dropped directly into liquid nitrogen contained in disposable polythene beakers.…”

Section: Organismsmentioning

confidence: 99%

The preservation of gonococci in liquid nitrogen

Ward

Watt

1971

J Clin Pathol

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SYNOPSIS Gonococci suspended in 1 % proteose peptone containing 8 % glycerol can be snap frozen in liquid nitrogen without detectable loss on thawing. This recovery rate has allowed the use of frozen organisms as the starting inoculum for the bulk growth of gonococci and to preserve gonococci both in urethral pus and after primary subculture for use in studies on gonococcal virulence.The method described for freezing urethral pus on charcoal swabs should make it possible to transport infected specimens from areas lacking adequate laboratory facilities.The long-term storage of standard strains of Neisseria gonorrhoeae is conveniently achieved by freeze drying but the recovery rates are poor, usually less than 5 % (Brookes and Heddn, 1966 CULTUREUrethral pus was cultured on Difco G.C. medium base containing dextrose 4 mg/ml, glutamine 100 ,ug/ml, ferric nitrate 10 ,ug/ml, and co-carboxylase 0-2 ,ug/ml (White and Kellogg, 1965 (Kocka and Bretz, 1969) as protective agents. Duplicate 0-1 ml volumes containing about 107 gonococci were dropped directly into liquid nitrogen contained in disposable polythene beakers. The frozen pellets were stored in screw-capped plastic ampoules (Sterilin Ltd) in a liquid nitrogen refrigerator.Urethral pus was suspended in 8 % glycerol peptone and 0.1 ml volumes were frozen either immediately after incubation at 37°C for 15 minutes or after homogenization using a Teflon grinder (Pierce, Dubos, and Schaefer, 1953). A further 0 1 ml of exudate was incubated at 37°C for 15 min in 8% glycerol peptone containing 5 % saponin. Pellets were thawed rapidly by dropping into 0-9 ml of 1% proteose peptone maintained at 37°C in a water bath. In both sets of experiments the results of duplicate viable counts on each of two frozen samples were averaged and expressed as a percentage of the starting inoculum.In a further series of experiments urethral exudates were collected on charcoal-impregnated swabs which were broken off into ampoules containing 0 4 ml of 8% glycerol peptone. After remaining at room temperature for periods of one to three hours, the swabs were cultured and then frozen by immersing the ampoules in liquid nitrogen. 122 on 11 May 2018 by guest. Protected by copyright.

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Survival ofEscherichia coli after storage in various frozen menstrua

Cited by 6 publications

References 27 publications

DNA Shuttling Between Plasmid Vectors and a Genome Vector: Systematic Conversion and Preservation of DNA Libraries Using the Bacillus subtilis Genome (BGM) Vector

DNA Shuttling Between Plasmid Vectors and a Genome Vector: Systematic Conversion and Preservation of DNA Libraries Using the Bacillus subtilis Genome (BGM) Vector

Interpretation of the EC method for the detection of latent Corynebacterium sepedonicum infections in potato¹

The preservation of gonococci in liquid nitrogen

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Survival ofEscherichia coli after storage in various frozen menstrua

Cited by 6 publications

References 27 publications

DNA Shuttling Between Plasmid Vectors and a Genome Vector: Systematic Conversion and Preservation of DNA Libraries Using the Bacillus subtilis Genome (BGM) Vector

DNA Shuttling Between Plasmid Vectors and a Genome Vector: Systematic Conversion and Preservation of DNA Libraries Using the Bacillus subtilis Genome (BGM) Vector

Interpretation of the EC method for the detection of latent Corynebacterium sepedonicum infections in potato1

The preservation of gonococci in liquid nitrogen

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Interpretation of the EC method for the detection of latent Corynebacterium sepedonicum infections in potato¹