1、BRITISH STANDARDBS EN ISO 13366-2:2006Incorporating corrigendum no. 1Milk Enumeration of somatic cells Part 2: Guidance on the operation of fluoro-opto-electronic countersThe European Standard EN ISO 13366-2:2006 has the status of a British StandardICS 67.100.10g49g50g3g38g50g51g60g44g49g42g3g58g44g
2、55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 13366-2:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October
3、 2006 BSI 2007ISBN 978 0 580 59227 0National forewordThis British Standard is the UK implementation of EN ISO 13366-2:2006, incorporating corrigendum June 2007. It supersedes BS EN ISO 13366-2:1997 and BS EN ISO 13366-3:1997 which are withdrawn.The UK participation in its preparation was entrusted t
4、o Technical Committee AW/5, Chemical analysis of milk and milk products.A list of organizations represented on AW/5 can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.C
5、ompliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date Comments17251Corrigendum No. 131 August 2007 Change to supersession information in the national foreword, EN title page and the EN foreword.EUROPEAN STANDARDNORME EUROPENN
6、EEUROPISCHE NORMEN ISO 13366-2October 2006ICS 67.100.10 Supersedes EN ISO 13366-2:1997 and EN ISO 13366-3:1997 English VersionMilk - Enumeration of somatic cells - Part 2: Guidance on theoperation of fluoro-opto-electronic counters (ISO 13366-2:2006)Lait - Dnombrement des cellules somatiques - Parti
7、e 2:Lignes directrices pour la mise en oeuvre des compteursfluoro-opto-lectroniques (ISO 13366-2:2006)Milch - Zhlung somatischer Zellen - Teil 2: Leitfaden zumBetrieb fluoreszenzoptoelektronischer Zhlgerte (ISO13366-2:2006)This European Standard was approved by CEN on 29 September 2006.CEN members a
8、re bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to t
9、he Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same statu
10、s as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Slo
11、venia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN nat
12、ional Members.Ref. No. EN ISO 13366-2:2006: EForeword This document (EN ISO 13366-2:2006) has been prepared by Technical Committee ISO/TC 34 “Agricultural food products“ in collaboration with Technical Committee CEN/TC 302 “Milk and milk products - Methods of sampling and analysis“, the secretariat
13、of which is held by NEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2007, and conflicting national standards shall be withdrawn at the latest by April 2007. This document supersedes EN
14、ISO 13366-2:1997 and EN ISO 13366-3:1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hu
15、ngary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 13366-2:2006 has been approved by CEN as EN ISO 13366-2:2006 without any modific
16、ations. EN ISO 13366-2:2006Reference numbersISO 13366-2:2006(E)IDF 148-2:2006(E)INTERNATIONAL STANDARD ISO13366-2IDF148-2Second edition2006-10-01Milk Enumeration of somatic cells Part 2: Guidance on the operation of fluoro-opto-electronic counters Lait Dnombrement des cellules somatiques Partie 2: L
17、ignes directrices pour la mise en uvre des compteurs fluoro-opto-lectroniques EN ISO 13366-2:2006ii iiiContents Page Foreword iv Foreword. v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle. 2 5 Factors affecting the results of measurements. 2 5.1 Sample bottles 2 5.2 Sa
18、mpling 2 5.3 Preservation 3 5.4 Sample storage and transport. 3 5.5 Interfering substances . 3 5.6 Sample quality at analysis . 4 5.7 Applied chemicals 4 5.8 Instrument condition 4 5.9 Working factor. 5 5.10 Testing volumes 5 6 Calibration . 5 6.1 Reference materials 5 6.2 Calibration procedure. 6 7
19、 Sampling 8 8 Determination 8 9 Checks on performance in routine operation 8 9.1 Blank checks . 8 9.2 Carry-over effect . 8 9.3 Ratio of reagent volume and test sample volume. 9 9.4 Pilot checks . 9 9.5 Additional instrument surveillance. 9 9.6 Repeatability 9 9.7 Intralaboratory reproducibility 10
20、9.8 External comparisons 10 10 Specific remarks for the use with milk from different species 10 10.1 General. 10 10.2 Cow milk 10 10.3 Goat milk 10 10.4 Sheep milk . 11 10.5 Buffalo milk . 11 11 Precision 11 11.1 Repeatability 11 11.2 Intralaboratory reproducibility 11 11.3 Reproducibility 12 12 Tes
21、t report . 12 Bibliography . 13 EN ISO 13366-2:2006iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees.
22、Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the Internat
23、ional Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Stand
24、ards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subjec
25、t of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 13366-2IDF 148-2 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (IDF). It is being published joint
26、ly by ISO and IDF. This edition of ISO 13366-2IDF 148-2 cancels and replaces ISO 13366-2:1997 and ISO 13366-3:1997, which have been technically revised. ISO 13366 consists of the following parts, under the general title Milk Enumeration of somatic cells: Part 1: Microscopic method (Reference method)
27、 Part 2: Guidance on the operation of fluoro-opto-electronic counters EN ISO 13366-2:2006vForeword IDF (the International Dairy Federation) is a worldwide federation of the dairy sector with a National Committee in every member country. Every National Committee has the right to be represented on the
28、 IDF Standing Committees carrying out the technical work. IDF collaborates with ISO in the development of standard methods of analysis and sampling for milk and milk products. Draft International Standards adopted by the Action Teams and Standing Committees are circulated to the National Committees
29、for voting. Publication as an International Standard requires approval by at least 50 % of the IDF National Committees casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IDF shall not be held responsible for identifyi
30、ng any or all such patent rights. ISO 13366-2IDF 148-2 was prepared by the International Dairy Federation (IDF) and Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is being published jointly by IDF and ISO. All work was carried out by the Joint ISO-IDF Act
31、ion Team on Automated methods, of the Standing Committee on Quality assurance, statistics of analytical data and sampling, under the aegis of its project leaders, Mrs S. Orlandini (IT) and Mr H.J.C.M. van den Bijgaart (NL). This edition of ISO 13366-2IDF 148-2 cancels and replaces IDF 148A:1995, met
32、hods B and C of which have been technically revised. ISO 13366 consists of the following parts, under the general title Milk Enumeration of somatic cells: Part 1: Microscopic method (Reference method) Part 2: Guidance on the operation of fluoro-opto-electronic counters EN ISO 13366-2:2006blank1Milk
33、Enumeration of somatic cells Part 2: Guidance on the operation of fluoro-opto-electronic counters 1 Scope This part of ISO 13366IDF 148 gives guidance on the operating conditions for counting somatic cells, in both raw and chemically preserved milk, using fluoro-opto-electronic somatic cell counters
34、 in which either a rotating disc technique or flow cytometry is applied in the counting section. The guidance is applicable to the counting of somatic cells in raw cow milk. The guidance is also applicable to raw milk of other species, such as goat, sheep and buffalo, if the specified prerequisites
35、are met. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 8196-1IDF 128
36、-1, Milk Definition and evaluation of the overall accuracy of indirect methods of milk analysis Part 1: Analytical attributes of indirect methods ISO 8196-2IDF 128-2, Milk Definition and evaluation of the overall accuracy of indirect methods of milk analysis Part 2: Calibration and quality control i
37、n the dairy laboratory ISO 13366-1IDF 148-1, Milk Enumeration of somatic cells Part 1: Microscopic method (Reference method) ISO Guide 34, General requirements for the competence of reference material producers ISO Guide 43-1, Proficiency testing by interlaboratory comparisons Part 1: Development an
38、d operation of proficiency testing schemes 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 8196-1IDF 128-1, ISO 8196-2IDF 128-2 and the following apply. 3.1 reference method method described in ISO 13366-1IDF 148-1 for the counting of somatic cells 3
39、.2 somatic cells those cells that show more than a threshold intensity of fluorescence due to the staining of DNA in their nuclei NOTE The number of somatic cells is expressed in cells per millilitre. EN ISO 13366-2:20062 4 Principle Fluoro-opto-electronic counters contain functions for the uptake o
40、f reagents and test sample, a mixing section and a counting section. In the mixing section, the test sample is mixed with a buffer and a stain solution. Part of the resulting mixture is transferred to the counting section and put onto an object plane. Each stained particle observed with a fluorescen
41、ce microscope produces an electrical pulse that is filtered, amplified and recorded. The resulting pulse height distribution is electronically processed, whereby discrimination is made between noise signals and pulses that are attributed to stained somatic cells. The discriminator level can either b
42、e fixed or dynamic. In the mixing section, closely controlled volumes of test sample and buffer/stain solutions are dosed and mixed. Mixing can take place in a cup, a mixing chamber, a centrifuge, a sample loop or in the tubing leading to a flow cell. In the counting section, either disc cytometry o
43、r flow cytometry can be applied. In the case of disc cytometry, a thin film of the mixture is brought through a nozzle to the top of a vertical rotating disc. This rotating surface acts as a moving object plane for a fluorescence microscope. When using flow cytometry, part of the mixture is placed i
44、n the high-speed flow of a surrounding sheath liquid in a capillary flow cell. Through acceleration, the mixture forms a thin string in which the somatic cells are dynamically focused and aligned. This string then passes the objective of a fluorescence microscope. Some instruments contain two channe
45、ls in the counting section. In terms of analytical quality assurance, such a situation should be considered equivalent to working with two separate units, so the performance should be evaluated separately for each channel. 5 Factors affecting the results of measurements 5.1 Sample bottles Sample bot
46、tles should be fit for use; i.e. to transfer test samples from the point of sampling to the laboratory without loss or damage. Care is to be exercised that sample bottles are leak-proof and that a proper empty volume is left. Too large an empty volume can facilitate churning; too small an empty volu
47、me can cause problems with mixing. 5.2 Sampling 5.2.1 General Sampling materials (i.e. sample bottles, beakers and sampling devices) should be clean and dry. Where automatic samplers are used, these should have been properly validated. Test samples should preferably be cooled immediately after sampl
48、ing to between 0 C and 6 C and be kept at that temperature until counting (see 5.4) rather than being preserved. Freezing should be avoided. If preservation is necessary, suitable means for chemical preservation of test samples are described in 5.3. 5.2.2 Bulk milk samples Thorough mixing of the raw
49、 bulk milk to be sampled is essential. Somatic cells will concentrate in the upper and lower layers in the case of insufficient stirring. 5.2.3 Milk samples from individual animals The release of somatic cells in the milk during milking is uneven. When the aim is to produce a representative counting result for a whole milking, it is essential that a representative sample of the whole milking be obtained. For diagnostic purposes, a sample of a partial milking may suffice. EN ISO 13366-2:200635.3 Preservation If chemical p
