THIOGLYCOLLATE FLUID MEDIUM EUROPEAN, USP
CAT Nº: 1508
For the cultivation of aerobic and anaerobic microorganisms in sterility tests
FORMULA IN g/l
Pancreatic Digest of Casein
15.00
L-Cystine
0.50
Glucose Monohydrate
5.00
Sodium Thioglycollate
0.50
Yeast Extract
5.00
Resazurin
0.001
Sodium Chloride
2.50
Bacteriological Agar
0.75
Final pH 7.1 ± 0.2 at 25ºC
PREPARATION
Suspend 29.0 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent
agitation. Boil for one minute until complete dissolution. Dispense into appropriate containers and sterilize in autoclave at
121°C for 15 minutes. The prepared medium should be stored at 2-8°C. The color is clear amber with a pink upper
layer. Cool before using and store in the dark.
The dehydrated medium should be homogeneous, free-flowing and light beige in color. If there are any physical
changes, discard the medium.
Once prepared it can be used some time after preparation until it is 30% oxidized, which is indicated by a pink color on
the Resazurin surface. If the oxidation is greater, reheat the medium only once, with steam or boiling water, cool it and
use.
USES
THIOGLYCOLLATE FLUID MEDIUM is used for detecting microorganisms in sterility tests, according to the formula
specified in the European Pharmacopoeia, USP in the Paragraph 2.6.1 Sterility.
Casein peptone provides nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is a source of
vitamins, particularly of the B-group. Sodium thioglycollate neutralizes the bacteriostatic effect of the compounds used
as preservatives in pharmaceutical preparations, especially injectables. Sodium thioglycollate and L-Cystine lower the
oxidation-reduction potential by removing oxygen to maintain a low pH. Dextrose is the carbohydrate energy source and
allows for a rapid and vigorous growth. Sodium chloride supplies essential electrolytes for transport and osmotic
balance. Resazurin is an oxidation indicator, turning from pink (aerobic) to colorless (anaerobic conditions).
Bacteriological agar delays the dispersion of CO2 and diffusion of O2.
With this medium it is not necessary to use a cap of sterile paraffin oil or incubate in special containers for anaerobes.
The anaerobic organisms develop at the bottom of the tube, the microaerophiles in the middle of the medium and the
aerobes in the top oxidized layer.
Inoculate and incubate at a temperature of 35 ± 2°C . no more than 3 days.
The European Pharmacopoeia, USP recommend in the Paragraph 2.6.1 Sterility the following:
For products containing a mercurial preservative that cannot be tested by the membrane-filtration method, fluid
thioglycolate medium incubate at 20-25°C may be used instead of soya-bean casein digest medium.
For growth promotion test of aerobes, anaerobes and fungi, inoculate portions of Fluid thioglycollate medium with a
small number, not more than 100 CFU, of Clostridium sporogenes ATCC 11437, Pseudomonas aeruginosa ATCC 9027
and Staphylococcus aureus ATCC 6538.
1
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www.condalab.com
For sterility, incubate portions of the media for 14 days. No growth of microorganims occurs.
When the material in study contains other preservatives, use a sufficient amount of thioglycollate to dilute the inoculum
beyond its bacteriostatic strength level.
MICROBIOLOGICAL TEST
The following results were obtained from type cultures in the performance of the medium after incubation at a
temperature of 35 ± 2°C and observed after 24 hours.
Microorganisms
Growth
Inoculum cfu/ml
Recovery Rate %
Bacillus subtilis ATCC 6633
Good
10-10
50
**Candida albicans ATCC 10231
Good
≤ 100
50
Neisseria meningitidis ATCC 13092
Good
10-10
50
* Staphylococcus aureus ATCC 6538
Good
≤ 100
70
*Clostridium sporogenes ATCC 11437
Good
≤ 100
50
*Pseudomonas aeruginosa ATCC 9027
Good
≤ 100
50
Bacteroides fragilis ATCC 25285
Good
10-10-2
50
Staphylococcus aureus ATCC 25923
Good
-2
10-10
70
Streptococcus pyogenes ATCC 19615
Good
10-10-2
50
**Aspergillus brasiliensis ATCC 16404
Good
≤ 100
50
-2
-2
*According to European Pharmacopoeia, USP Inoculum no more than100 CFU. Incubate at 30-35ºC not more than 3
days
** According European Pharmacopoeia, USP Inoculum no more than 100 CFU. Incubate at 30-35ºC.not more 5days
BIBLIOGRAPHY
Brewer. JAMA, 115. 1940. Vera. J. Bact. 47:59, 1944. Pittman. J. Bact. 51:19, 1946.
Kurtin A. J. Clin. Path. 30:229, 1958.
European Pharmocopoeia 7.0
EP
STORAGE
25ºC
Once opened keep powdered medium closed to avoid hydration.
2ºC
2
LABORATORIOS CONDA, S.A.
www.condalab.com