Spectra/Por® 7 Standard RC tubing is chemically treated to remove any trace levels of heavy metals and sulfide compounds that may be present in dry Spectra/Por® 1-5 and pre-wetted Spectra/Por® 6 Standard RC membranes. Ready-to-use Spectra/Por 7 is also already equilibrated in water and packaged wet in a preservative solution of 0.05% sodium azide. Simply rinse away the preservative solution with DI water, load the sample and dialyze. The tubing is available in 5 m/roll to provide better economy for applications requiring larger amounts of tubing.