Sterilising sample tubes

[lphillips]

Dear Forum,
A problem that I am sure has been answered many times has arisen in my lab. It is the question of effectively sterilising your run of the mill 1.5ml HPLC screw top vial. We have tried autoclaving but some impurity in the water supply leaves them in less than pristine condition. We have been told that irradiation will colour the vials an amber colour which we do not wish to happen. The use of ethylene oxide maybe an alternative but this presents problems in terms of finding someone to do this.

Does anybody have another procedure we can use for sterilising?

[HW Mueller]

Depending on the application it might suffice to wash the vials with EtOH, MeOH, ACN, or even with these containing some H2O (see contributions on keeping bugs out of mobile phases). Washing also removes pyrogens.

[Peter Apps]

I doubt that you will see a colour change in the vials with a sterilising dose of radiation - you really have to blast it with gamma rays to get it to change colour. A more serious problem is that the radiation might make the septa go hard - it causes more crosslinking in the silicone rubber.

If you only want to sterilise the vial (and not the cap) you can use dry heat.

Peter