1、Designation: D 4196 05Standard Test Method forConfirming the Sterility of Membrane Filters1This standard is issued under the fixed designation D 4196; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes a test to confirm the sterilityof either manufacturer presterilized or user-sterilized analyticalmembrane filt
3、ers.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenc
4、ed Documents2.1 ASTM Standards:2D 1129 Terminology Relating to WaterD 1193 Specification for Reagent Water2.2 Other Standard:The United States Pharmacopeia, Current Edition3(Sec-tions on Sterilization and Sterility Testing)3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod
5、, refer to Terminology D 1129.4. Summary of Test Method4.1 The membrane filters are immersed in sterile culturemedia and incubated at temperatures that are suitable forgrowth of viable bacteria, fungi, and yeasts. Growth oforganisms is evidence that the filter has failed the test.5. Significance and
6、 Use5.1 This test method may be employed to check the sterilityof commercially procured sterile membrane filters. The testalso confirms that sterilized filters have not been contaminated.Additionally, this test may be used to monitor the efficacy ofin-house sterilization procedures. Filter packages
7、that haveobvious packaging defects should not be tested because steril-ity may have been compromised.6. Reagents and Materials6.1 Purity of Water Unless otherwise indicated, referenceto water shall be understood to mean Type II reagent gradewater in accordance with Specification D 1193.6.2 MediaUse
8、commercially available dehydrated media.Dissolve and sterilize by autoclaving, in accordance with themanufacturers directions.6.2.1 Fluid Thioglycollate Medium (Note)Dispense40-mL aliquots into suitable-sized vessels with screw-capclosure, providing a ratio of surface area to depth of medium sothat
9、no more than the upper half of the medium has initiallyundergone a color change indicative of oxygen uptake. Whenready for use, not more than the upper one tenth of the mediumshould be pink. The medium may be restored once by heatingin free-flowing steam until the pink color disappears. The pH ofthe
10、 medium, after autoclaving, should be 7.1 6 0.2.NOTE 1If stored at 2 to 5C in sealed containers, the media may beused for 1 year provided they are tested for the growth-promotingproperties every 3 months.6.2.2 Soybean-Casein Digest Medium (Note)Dispense40-mL aliquots into suitable vessels with screw
11、-cap closure.The pH after autoclaving should be 7.3 6 0.2.6.2.3 Perform a sterility test on each lot of autoclavedmedium by incubating ten representative containers of eachmedium, for not less than 10 days, at the specified testtemperature.6.2.4 Perform a growth-promotion test, as described below,on
12、 each lot of autoclaved medium.6.2.4.1 Inoculate duplicate test containers of each mediumseparately with less than 100 of each of the below listedmicroorganisms. Incubate 7 days at the temperatures listedbelow:Medium Test OrganismsATemperature, CFluid thioglycollate Bacillus subtilis (ATCC 6633)B30
13、to 35Candida Albicans (ATCC 10231) 30 to 35Soybean-casein Bacillus subtilis (ATCC 6633)B20 to 25Candida albicans (ATCC 10231) 20 to 25AAvailable from the American Type Culture Collection, 12301 Parkview Drive,Rockville, MD 20852.1This test method is under the jurisdiction of ASTM Committee D19 on Wa
14、terand is the direct responsibility of Subcommittee D19.08 on Membranes and IonExchange Materials.Current edition approved Jan. 1, 2005. Published February 2005. Originallyapproved in 1982. Last previous edition approved in 1998 as D 4196 82 (1998).2For referenced ASTM standards, visit the ASTM webs
15、ite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Mack Publishing Co., Easton, PA 18042.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West C
16、onshohocken, PA 19428-2959, United States.BIf a non-spore-forming organism is desired, use Micrococcus Luteus (ATCC9341).6.2.4.2 The media are satisfactory if growth of the micro-organisms is apparent within 7 days. The growth-promotiontest may be performed simultaneously with the sterility test oft
17、he media. However, the media sterility test will be consideredinvalid if the growth promotion test shows no growth.7. Sterility Test Procedure7.1 CautionSterility tests should be performed in a lami-nar flow hood having an air velocity of 30 6 2 m (90 6 5ft)/min. The working surface of the laminar f
18、low bench shouldbe wiped with a suitable disinfectant 30 min prior to perform-ing the test. The exterior surfaces of all containers, equipment,etc., used in conjunction with sterility testing should bedisinfected and placed into the laminar flow bench 30 min priorto performing the test. The operator
19、 should wear a sterile gownand sterile rubber gloves. The gloves should be disinfected,with a 70 % (V/V) alcohol solution, each time after touching anonsterile surface.7.2 Aseptically open the packets of membrane filters.7.3 Using sterile forceps, aseptically place one membranefilter into each of 20
20、 containers of the fluid thioglycollatemedium.7.4 Using sterile forceps, aseptically place one membranefilter into each of 20 containers of soybean-casein digestmedium.7.5 Incubate the fluid thioglycollate medium at 30 to 35Cfor at least 14 days.7.6 Incubate the soybean-casein digest medium at 20 to
21、25C for 14 days.7.7 Examine all containers for the growth of microorgan-isms over the 14-day incubation period. Turbidity is indicativeof microbial growth.8. Interpretation of Results8.1 The membrane filters pass the test for sterility if nogrowth occurs during the specified incubation period. Resul
22、tsare valid in defined experimental conditions at the time thesample was collected and treated, and for a period that cannotexceed the incubation period used in the method.9. Retests9.1 If microbial growth is observed in the sterility tests, thefollowing retests are permitted:9.2 First Retest:9.2.1
23、Retest an additional 40 membranes from the lot. Ifmicrobial growth does not occur during the specified incuba-tion period, the membrane filters pass the test for sterility.9.2.2 If microbial growth occurs in the first retest, isolate themicroorganism(s) and compare them to the organisms isolatedfrom
24、 the sterility test. If they cannot be readily differentiated,a second retest may be performed.9.3 Second Retest:9.3.1 Test an additional 80 membranes from the lot.9.3.2 If growth is not apparent, the membrane filters passthe test for sterility. If growth occurs in the second retest, themembrane fil
25、ters fail to meet the requirements for the test forsterility.10. Precision and Bias10.1 Since this is a pass-fail test, a precision statement is notappropriate for this test method.10.2 Bias of this test method depends upon the strictadherence to good aseptic technique required in performing thetest
26、s.11. Keywords11.1 filters; membrane; sterilityASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights,
27、and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revi
28、sion of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you
29、shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 4196 052
