ASTM D4196-05

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D4196 – 05
Standard Test Method for
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Confirming the Sterility of Membrane Filters
This standard is issued under the fixed designation D4196; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Additionally, this test may be used to monitor the efficacy of
in-house sterilization procedures. Filter packages that have
1.1 This test method describes a test to confirm the sterility
obvious packaging defects should not be tested because steril-
of either manufacturer presterilized or user-sterilized analytical
ity may have been compromised.
membrane filters.
1.2 This standard does not purport to address all of the
6. Reagents and Materials
safety concerns, if any, associated with its use. It is the
6.1 Purity of Water— Unless otherwise indicated, reference
responsibility of the user of this standard to establish appro-
to water shall be understood to mean Type II reagent grade
priate safety and health practices and determine the applica-
water in accordance with Specification D1193.
bility of regulatory limitations prior to use.
6.2 Media—Use commercially available dehydrated media.
2. Referenced Documents Dissolve and sterilize by autoclaving, in accordance with the
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manufacturer’s directions.
2.1 ASTM Standards:
6.2.1 Fluid Thioglycollate Medium (Note)—Dispense
D1129 Terminology Relating to Water
40-mL aliquots into suitable-sized vessels with screw-cap
D1193 Specification for Reagent Water
closure,providingaratioofsurfaceareatodepthofmediumso
2.2 Other Standard:
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that no more than the upper half of the medium has initially
The United States Pharmacopeia, Current Edition (Sec-
undergone a color change indicative of oxygen uptake. When
tions on Sterilization and Sterility Testing)
ready for use, not more than the upper one tenth of the medium
3. Terminology should be pink. The medium may be restored once by heating
infree-flowingsteamuntilthepinkcolordisappears.ThepHof
3.1 Definitions—For definitions of terms used in this test
the medium, after autoclaving, should be 7.1 6 0.2.
method, refer to Terminology D1129.
NOTE 1—If stored at 2 to 5°C in sealed containers, the media may be
4. Summary of Test Method
used for 1 year provided they are tested for the growth-promoting
4.1 The membrane filters are immersed in sterile culture properties every 3 months.
media and incubated at temperatures that are suitable for
6.2.2 Soybean-Casein Digest Medium (Note)—Dispense
growth of viable bacteria, fungi, and yeasts. Growth of
40-mL aliquots into suitable vessels with screw-cap closure.
organisms is evidence that the filter has failed the test.
The pH after autoclaving should be 7.3 6 0.2.
6.2.3 Perform a sterility test on each lot of autoclaved
5. Significance and Use
medium by incubating ten representative containers of each
5.1 This test method may be employed to check the sterility
medium, for not less than 10 days, at the specified test
of commercially procured sterile membrane filters. The test
temperature.
also confirms that sterilized filters have not been contaminated.
6.2.4 Perform a growth-promotion test, as described below,
on each lot of autoclaved medium.
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6.2.4.1 Inoculate duplicate test containers of each medium
This test method is under the jurisdiction of ASTM Committee D19 on Water
and is the direct responsibility of Subcommittee D19.08 on Membranes and Ion separately with less than 100 of each of the below listed
Exchange Materials.
microorganisms. Incubate 7 days at the temperatures listed
Current edition approved Jan. 1, 2005. Published February 2005. Originally
below:
approved in 1982. Last previous edition approved in 1998 as D4196 – 82 (1998).
DOI: 10.1520/D4196-05.
A
2 Medium Test Organisms Temperature,° C
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
B
Fluid thioglycollate Bacillus subtilis (ATCC 6633) 30 to 35
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Candida Albicans (ATCC 10231) 30 to 35
Standards volume information, refer to the standard’s Document Summary page on
B
Soybean-casein Bacillus subtilis (ATCC 6633) 20 to 25
the ASTM website.
Candida albicans (ATCC 10231) 20 to 25
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Mack Publishing Co., Easton, PA 18042.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D4196 – 05
A
Available from the American Type Culture Collection, 12301 Parkview Drive,
8. Interpretation of Results
Rockville, MD 20852.
B
If a non-spore-forming organism is desired, use Micrococcus Luteus (ATCC 8.1 The membrane filters
...