I was filtering a couple of days ago and got lost in my steps, I'm pretty absent minded these days, so I decided to write these down for my own use. I wrote these based on the video I posted from Peptide test. It seems like a lot of needles, but needles are so inexpensive, it makes sense to discard when they are man handled. I'm sure I'll pick up speed the more and more I filter and probably won't need a checklist eventually.
Step 0. Thoroughly wipe down the work surface with 70% isopropyl alcohol (IPA) and allow to fully dry before placing any materials. Wipe all vial stoppers and cartridge septa with 70% IPA and allow to dry prior to use.
Step 1. Reconstitute lyophilized peptide per standard protocol.
Step 2. Detach the reconstitution needle from the luer-lock syringe; safely discard the needle.
Step 3. Insert a sterile venting needle into the destination vial or cartridge to equalize pressure during transfer. (Optional: fit the venting needle with a 0.22 µm filter to maintain sterility of the headspace prior to insertion if so desired.)
Step 4. Attach a fresh drawing needle to the luer-lock syringe.
Step 5. Draw the full volume of reconstituted peptide into the syringe.
Step 6. Detach the drawing needle from the luer-lock syringe; safely discard the needle.
Step 7. Attach a sterile 0.22 µm syringe filter directly to the luer-lock tip of the syringe. Attach a sterile needle to the outlet port of the filter.
Step 8. Pierce the septum of the destination vessel with the outlet needle and express the peptide solution through the filter into the destination vessel.
Optional: Filter Recovery Flush
(Recovers the dead volume / hold-up volume retained within the filter housing — typically 0.1–0.2 mL (10–20 units on a U-100 syringe), depending on filter size.)
Step 9. With the venting needle still seated in the destination vessel, carefully disconnect the luer-lock syringe from the inlet of the filter, leaving the filter and outlet needle in place in the septum.
Step 10. Attach a fresh drawing needle to the now-empty luer-lock syringe.
Step 11. Draw an appropriate volume of bacteriostatic water into the syringe — typically equal to or slightly greater than the filter's rated hold-up volume (e.g., 0.1–0.2 mL / 10–20 units on a U-100 syringe).
Step 12. Detach the drawing needle from the luer-lock syringe; safely discard the needle.
Step 13. Reconnect the luer-lock syringe (containing bacteriostatic water) to the inlet port of the filter assembly from Step 9.
Step 14. Slowly express the bacteriostatic water through the filter to flush retained peptide into the destination vessel.
Step 15. Remove the filter assembly and venting needle. Cap or seal the destination vessel. Gently swirl or invert to mix the flush volume with the filtered peptide. Label with peptide name, concentration (adjusted for flush dilution if relevant), reconstitution date, and diluent used.
