CONTROLLED COPY
Centre for Biological Engineering
Standard Operating Procedure
SOP025
Title: USE AND MAINTENANCE OF THE SYSTEC VX 95 AUTOCLAVES
Location:
Autoclave Room, H31, CBE
Version 004
Effective Date: 28
th
June 2020
Review 28
th
June 2022
Written by: A. Chandra
Reviewed by: P.Hourd
Approved by: R.I.Temple
Page 14 of 26
Mastercopy
5.3.6.1. Cycle Selection
Only
use these cycles for liquids!
WARNING:
The sterilization of liquids in solids cycles is highly dangerous through boiling
delays or exploding vessels and can result in serious injuries. For this reason, liquids may only
be sterilized using the cycle Nos. 6 to 11, which are designed for this purpose!
Liquids MUST be sterilized in OPEN vessels. For the sterilization of OPEN vessels you can use one of
the cycles with water cooling (Nos. 8, 9 or 10) as well as the cycle without active cooling (No. 11).
Liquids in hermetically closed vessels can be sterilised using the option for rapid cooling with support
pressure supply (No's 8, 9, and 10). If the sterilisation of liquid in CLOSED vessels is required users
MUST first consult the Responsible Person.
NOTE:
These cycles have NOT been validated. If liquid items are to be used in critical or costly
experimental procedures it is recommended that this cycle is validated
.
(i)
CYCLE 11 (Liquids),
with an operating cycle fixed at 121
°
C and 15 minutes,
MUST be used for the sterilisation of liquids in suitable OPEN vessels, without active
cooling. DO NOT USE FOR STERILISATION OF LIQUIDS IN TIGHTLY-SHUT
VESSELS!
(ii)
CYCLES 8-10 (Liquids)
should be used for sterilisation of heat sensitive liquids
in suitable
OPEN or HERMETICALLY CLOSED vessels only.
By means of rapid
cooling with cooling water with support pressure by filtered compressed air, the cooling
periods are reduced by approx. 70% in comparison to normal cooling. The loss of liquid
in the item being sterilized during rapid cooling with cooling water and support pressure
amounts to < 1%.
The operator can set a cooling rate that fixes a minimum cooling time, depending on the
cooling system and the loading. The minimum cooling time ensures that, regardless of
the unloading temperature, the autoclave can only be opened when this cooling time
has elapsed.
The cooling rate (K/min) must be determined and set by the user,
depending on the type of load.
WARNING:
With closed containers, water cooling may only be used in conjunction with
support pressure supply. If no support pressure supply is available, the containers must
be open!
(iii)
The autoclave is fitted with a temperature dependent door lock. For sterilisation
of liquids, the flexible temperature sensor MUST therefore be placed in the liquid or in a
