Surface sterilisation

Thorough clean downs should be carried out as often as the production schedule will allow, during which all accretions, build up of caked powders etc., are removed by scraping, power steam cleaning or alkali soak, back to the bare surface. Sterilisation can then he achieved by a biocidal rinse, this protected rinse water then being used for the next paint batch produced. Filling equipment, especially nozzles, must be similarly treated. 

Sterilization. Seeds of each wheat accession were surface-sterilised by soaking in 70% ethanol for 2.5 min, followed by four rinses in sterilised distilled water. They were then soaked in 2.5% sodium hypochlorite solution for 15 min, followed by five rinses in sterilized distilled water. 

Light frequently inhibits the growth of bacteria, although there are species which readily survive in the light (UV light has surface sterilising properties). 

This is not recognised by the BP or USP as a formal sterilization process. UV light is basically a surface sterilising process and is used in some sterile (class 1) areas to reduce any airborne contamination. 

In the food industry such equipment would use either a presterilised web exposed by a removable peelable layer, or UV or hydrogen peroxide as an on-line surface sterilising agent. Currently none of these would be acceptable for a pharmaceutical operation, although use for sterile oral liquids might bear consideration. 

Open with sterile scalpel on surface sterilised with ethanol... 

Inoculate 1 ml sterile L Broth (containing desired antibiotic) from a single colony bearing the desired plasmid. This is done with a toothpick that has been surface sterilised (in alcohol, flamed prior to use), touched lighdy to the desired colony on a plate. A saturated liquid stock may also be used. 

The carbohydrate (again often molasses, 15 - 25%) and added nutrients are pH-adjusted to below 4.0 and, for Otis process, have to be sterilised. It is necessary to add potassium hexacyanoferrate but greater care is required in this process compared to surface culture. The A. niger seems to be more sensitive to and more easily inhibited by hexacyanoferrate in submerged culture. It is essential however to lower the ferrous and manganese concentrations, probably below 200 and 5 pg l1 respectively, to optimise the performance of A. niger. 

Impact frustration A process typified by the extinction of the dinosaurs where the Earth s surface may have been sterilised of all life forms by the impact of a large meteorite or comet... 

Mars rovers, Spirit and Opportunity, could deposit Earth bacteria on the Martian surface, which fortuitously could find an environment in which to colonise. One possible false alarm for Martian life exploration is that evidence is found on the Martian surface of life on Earth. Extreme measures have been taken with the NASA spacecraft to use exposure to the UV radiation from the Sun to sterilise the spacecraft, rotating the various surfaces to face a prolonged exposure, but none of this could guarantee a sterile spacecraft. 

The intensity of ionising radiation at the earth s surface is not high enough to significantly affect plastics, hence radiation exposure tests are only required in connection with applications in nuclear plant and possibly where radiation is used for sterilisation or to induce crosslinking. 

Place the dead or the anaesthetised mouse on its back or right side on a clean surface. Wipe the abdomen and left side thoroughly with 70% alcohol to clean it off and to wet the fur — this is not going to sterilise the animal s surface, but as long as the spleen does not touch the surface, it will not result in contamination. 

There are a number of well-established systems for the aseptic packaging of liquids. Notable among these are those packs constructed, box form, in situ on the filling line from a cardboard, aluminium, plastic laminate sheet, such as TetraPak or Combi-box. In the TetraPak system, the packing material enters the filling machine from a feed roll the sheet contact surface is sterilised with warm hydrogen peroxide solution it is formed into a tube, and its lower end is heat-sealed across the width the tube is filled, sealed at the upper end, cut and then folded into a box shape. This produces a continuous output of filled cartons with premium utilisation of bulk storage capacity. 

In the fust system the inner surface of a pre-made, open-necked bottle is sterilised. The sterility is maintained while the bottle is transferred to the aseptic filler. The layout of this type of filler is shown in Figure 9.1. The pre-made... 

The entire surface of the laminate is sterilised with hydrogen peroxide before it is filled and shaped into packs. This has proved to be a very efficient and safe technique. The filling takes place in a sterile environment which is small and has few moving parts. These are important factors that contribute to the integrity of the system. The packs are sealed through the liquid, which means they are completely filled and the contents are thus fully protected against oxidation. The brik format makes very effective use of materials and economical use of bulk volume in palletisation and distribution 93% is product and only 7% is primary and secondary packaging. 

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