BS EN 1650-2019 Chemical disinfectants and antiseptics – Quantitative suspension test for the evaluation of fungicidal or yeasticidal activity of chemical disinfectants and antiseptics used in food, industrial, domestic and institutional areas – Test method and requirements (phase 2, step 1).
The apparatus shall have a filter holder oral least 50 ml volume. It shall be suitable for use with filters of diameter 47 mm to 50mm and 045 pm pore size for steflhization of hard water ( bovine albumin (5.228.2 and and if the membrane illtration method Is used (5.5.3).
The vacuum source used shall give an even fihtratiusi flow rate. In order to obtain a uniform distribution o(the microorganisms over the membrane and to prevent overlong filtration, the device shall be set so as to obtain th filtration of 100 ml of rinsing liquid in 20 s to 40s.
53.2.8 Relrigerator. capable of being controlled at 2 C toO C.
53.2.9 Graduated pipette’s, of nominal capacities 10 ml and I ml and 0.1 ml. or calibrated automatic pipettes. Prt,1 dishes. (plates) of size 90mm to 100 mm.
5.3.2,11 Glass beads 3 mm to 4 mm in diameter VolumetrIc flasks Frftted filter, with porosity o140 pm to 100 pm according to ISO 4793. Flasks with ventilated caps.
5.4 Preparation of test organism suspensions and product test solutions
5.4.1 Test organism suspensions (test and validation suspension) General
For each test organism, two different suspensions shall b prepared: the test suspension to perlorm the test and lbs validat,iin wspcns1on to perform the controls and method validation Preservation and stock cultares of test organisms
The test organisms and their stock cultures shall be prepared and kept in accordance with EN 12353. 5.4.1 .3 Working culture of test organisms Carndldo o1bcsms (yeast)
In order to prepare the working culture of Con chda o?bscons (5.2.1). prepare a subculture from the stock
culture ( by streaking onto MEA ( slopes or plates ( and incubate ( After
42 h to 48 h. prepare a second subculture from the first subculture In the same way and incubate for
42 h to 48 h. From this second subculture, a third subculture may be produced in the same way. The
second and (If produced) third subcultures are the working cultures.
If it is not possible to prepare the second subculture on a particular day, a 72 h subculture may be used for subsequent cubcultuflng. provkied that the subculture has been kept in the incubator ( during the 72 h period.
Never produce and use a fourth subculture. Asperglllu.s brusfllenads (mould)
For AsperqlNass bronlwmis (5.2.1). use only the first subculture grown on MEA (5.22.3) In Petri dishes or flasks with ventiLited caps ( and l,icubale for 7 d to 9 d. No further subcultunng is needed. Do not stack the Petri dishes irlng the Incubaflon to improve the temperature hornogernzanon.BS EN 1650 pdf download.