You have to be careful when trying to save money on plastics; never forget that it is your sample or your customers valuable sample inside.  The ExtraGene centrifuge tubes, while inexpensive, are not cheap.  These are high quality clear polypropylene centrifuge tubes available in 50mL and 15mL sizes both sterile and non-sterile.  They come with an long cap for increased contamination resistance and the centrifuge tubes have a max RCF of 9,400g and a working temperature range of -20ºC to 121ºC and are autoclavable.  They are DNase and RNase free.  As a convenience to our customers we sell our centrifuge tubes in both bag and case quantities.  If you would like a sample please contact us.