ISO INTERNATIONAL STANDARD 4833-1 First edition 2013-09-01 Microbiology of the food chain - Horizontal method for the Part 1: Colony count at 3o °C by the pour plate technique Microbiologie de la chaine alimentaire - Méthode horizontale pour le dénombrement des micro-organismes- Partie 1: Comptage des colonies a 30 °C par la technique d'ensemencement en profondeur Reference number IS0 4833-1:2013(E) LSO @ IS0 2013 I without license from IHS Not for Resale IS0 4833-1:2013(E) COPYRIGHTPROTECTEDDOCUMENT ISO2013 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Case postale 56:CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland @ IS0 2013 - All rights reserved No reproductic networking permited without license from IHS Not for Resale IS0 4833-1:2013(E) Contents Page Foreword ..iv 1 Scope .1 2 Normative references .1 3 Terms and definitions 4 Principle ..2 5 Culture media and diluents .2 5.1 General. .2 5.2 Diluents .2 5.3 Agar medium: plate count agar (PCA) .2 5.4 Overlay medium (if necessary; see 9.2.7) ..3 6 Apparatus 7 Sampling. ..4 8 Preparation of test sample ..4 9 Procedure ..4 9.1 Test portion, initial suspension and dilutions .4 9.2 Inoculation and incubation .4 9.3 Counting of colonies. .5 10 Expression of results .5 10.1 Method of calculation. .5 10.2 Precision. .5 10.3 Interpretation of test results ..6 11 Test report 1 Annex A (informative) Use of the critical difference for the interpretation of results Bibliography .9 iii se with ISt thout license from IHS Not for Resale