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. Spectra/Por 7 Dialysis Trial Kits include 1 meter of pre-treated tubing, a pair of closures and 5 opening picks; ideal for small experiments or qualifying a membrane for a particular application.