SIST EN ISO 13366-1:1998

SLOVENSKI STANDARD
SIST EN ISO 13366-1:1998
01-avgust-1998
Mleko - Ugotavljanje števila somatskih celic - 1. del: Mikroskopska metoda (ISO
13366-1:1997)
Milk - Enumeration of somatic cells - Part 1: Microscopic method (ISO 13366-1:1997)
Milch - Zählung somatischer Zellen - Teil 1: Mikroskopisches Verfahren (ISO 13366-
1:1997)
Lait - Dénombrement des cellules somatiques - Partie 1: Méthode au microscope (ISO
13366-1:1997)
Ta slovenski standard je istoveten z: EN ISO 13366-1:1997
ICS:
67.100.10
SIST EN ISO 13366-1:1998 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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INTERNATIONAL
IS0
STANDARD
13366-l
First edition
1997-06-I 5
Milk - Enumeration of somatic cells -
Part 1:
Microscopic method
Lait - Dknombrement des cellules soma tiques -
Parfie I: Mkthode au microscope
Reference number
IS0 13366-l :1997(E)

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IS0 13366-l :1997(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work of
preparing International Standards is normally carried out through IS0
technical committees. 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. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards 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.
International Standard IS0 13366-1 was prepared by Technical
Committee lSO/TC 34, Agricultural food products, in collaboration with the
International Dairy Federation (IDF) and AOAC INTERNATIONAL, and will
also be published by these organizations.
IS0 13366 consists of the following parts, under the general title Milk -
Enumeration of soma tic cells:
Part I: Microscopic method
Electronic particle counter method
Part 2:
Part 3: Nuoro-opto-electronic method
Annex A of this part of IS0 13366 is for information only.
0 IS0 1997
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Internet central @ isocs.iso.ch
x.400
c=ch; a=40Onet; p=iso; o=isocs; s=central
Printed in Switzerland

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INTERNATIONAL STANDARD 0 Iso IS0 13366-I : 1997(E)
- Enumeration of somatic cells -
Milk
Part 1:
Microscopic method
WARNING - The use of this standard may involve hazardous materials, operations and equipment. This
standard does not purport to address all of the safety problems associated with its use. It is the
responsibility of the user of this standard to establish appropriate safety and health practices and to
determine the applicability of regulatory limitations prior to use.
1 Scope
This part of IS0 13366 specifies a method for counting somatic cells in both raw and chemically preserved milk. The
method is suitable for preparing standard test samples and for calibrating mechanized and automatic cell-counting
procedures.
2 Definition
For the purposes of this part of IS0 13366, the following definition applies.
2.1 somatic cells: Those cells with nuclei, that is, all leucocytes and epithelial cells.
3 Principle
Spreading of a test portion of the milk to be examined over a slide to form a film. Drying and staining of the film and
subsequent counting of the stained cells using a microscope. Multiplication of the number of cells counted in a
defined area by a working factor to give the number of cells per millilitre.
4 Reagents
WARNING - Tetrachloroethane is poisonous. Ethidium bromide is toxic. The preparation and application
of the dye solution shall be carried out in a fume cupboard. Use gloves for protection.
Use only reagents of recognized analytical grade, unless otherwise specified, and distilled or deionized water or
water of equivalent purity.
1

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@ IS0
IS0 13366-l :1997(E)
4.1 Dye solution
4.1 .l Composition
Ethanol 95 % (VW) 54,0 ml
Tetrachloroethane 40,O ml
Methylene blue 05 g
Acetic acid, glacial 6,0 ml
NOTE - As an alternative, tetrachloroethane may be replaced by the same amount of trichloroethane. Instead of methylene
blue, ethidium bromide can be used (see IS0 13366-3).
4.1.2 Preparation
Mix the ethanol and tetrachloroethane in a bottle. Heat in the water bath (5.1) set at 65 “C. Add the methylene blue
and mix carefully. Cool in a refrigerator to 4 “C and then add the glacial acetic acid. Pass the solution through an
appropriate filter (5.3) into an airtight bottle and store it as such. If necessary, filter again before use.
5 Apparatus
Usual laboratory equipment and, in particular, the following.
5.1 Water bath, capable of being maintained at a temperature of 65 “C + 5 “C.
5.2 Water bath, capable of being maintained at a temperature of 35 “C ~fi 5 “C.
5.3 Filter, resistant to the solvents used, with a pore size of between 10 pm and 12 pm or less.
5.4 Microscope, with magnification of between x 500 and x 1 000.
If ethidium bromide is used,
...