Centrifuging bacterial cultures - Fill those bottles! (Jan/25/2011 )

In this protocol, the centrifuge bottles are filled only a half or even a quarter full. Why? Why not 80% or even 100% of the nominal capacity?

Also, the different plastics used to manufacturer the bottles, PPCO, PC, PSF, FEP PTFE... how do I decide? (new ones will be purchased tomorrow for the purpose of preparing electrocompetent bacteria).

seanspotatobusiness on Tue Jan 25 19:17:21 2011 said:

According to Cole Palmer's website, factors include the clarity of the material (whether you can see through it easily), chemical resistance, spin-speed and subjectability to autoclave: The table here, gives some information on centrifuge tube plastics: http://www.coleparmer.co.uk/techinfo/techinfo.asp?htmlfile=Centrifuge_Temp.htm&ID=54

Also, I've read elsewhere that some bottles are actually supposed to be used at least 80% full, and others no more than 75%.

I wonder whether culture is allowed to touch the lid? I can't see why not - it should all be flung to the bottom of the bottle, anyway... Our rotor has a fixed angle.

Chemical resistance is a problem if you plan on doing larger scale plasmid preps where you are likely to be adding solvents such as isopropanol (even if it isn't mentioned in a kit, it is still usually there. I think it is in buffer QC for qiagen kits).