Filtering

Peptide Test- How to Filter Video: https://youtu.be/9YBj26vpHs0?si=U\_oD4f64da3ppx1l   A  practical study tested syringe filters (4mm vs 13mm) on reconstituted peptides, measuring volume loss and concentration via HPLC. Key findings: 4mm filters lose ~5-7% volume (0.05-0.07mL from 1mL), while 13mm lose ~28-29% (0.28-0.29mL)—use smaller filters for minimal waste. Peptide concentration changes were negligible (< practical impact), with some samples showing slight increases post-filtration (filters retain water, concentrating peptides). Bottom line: Filter for sterility, but choose 4mm PES 0.22µm to preserve yield.

Study Details

• Filter Comparison: 4mm = low volume loss (ideal for 1mL vials); 13mm = higher “dead volume” retention.​
• Concentration Impact: Minimal peptide adsorption; filtration primarily affects volume, not purity/potency.​
• Practical Tip: Air purge post-filtration recovers extra ~0.01mL from 4mm filters.

  For 22 micron filters, the Volumetric loss is: 4mm- Loss of .07ml 13mm- Loss of .28ml 33mm- Loss of .65ml   Full Study completed by Peptide Test: https://drive.google.com/file/d/1jFQsc6O77GApmaLtsufBHP623MnvBfm-/view?pli=1 Here is a video of their 4mm syringe capacity testing: https://www.youtube.com/watch?v=2w\_0VsAoKvU