I have only used the Tisch since they are available from the vendors I use most, There are brands on Amazon, but I've only seen the 13mm and up, which is too high a loss in pep for my liking..
I dont order from Amazon, because I have a shared Prime account with family members I dont want to have to explain the peptide paraphernalia to..lol
I would love to learn more about the info on brands and clog rate, do you have a link?
thanks.
I asked Gemini and it appears your choice of 4 mm is the correct one for peptide use:
Syringe Filter Peptide Loss
When selecting a syringe filter for peptide handling, the type of filter and its size significantly impact peptide loss rates. The membrane material plays a crucial role in minimizing sample loss; polyethersulfone (PES) and polyvinylidene fluoride (PVDF) are commonly used for biological samples due to their low protein binding properties, which helps reduce peptide adsorption and loss during filtration PES filters are particularly recommended for aqueous solutions and are effective in maintaining peptide integrity
Filter size directly affects volumetric loss. Studies show that a 4 mm syringe filter results in significantly less volume loss—approximately 5–7 units—compared to a 13 mm filter, which loses about 29 units when filtering a reconstituted peptide solution For volumes up to 4 mL, a 4 mm filter is optimal to minimize loss, while a 13 mm filter is more appropriate for larger volumes Larger filters (e.g., 25 mm and 33 mm) result in even greater peptide loss due to increased holdup volume
Regarding peptide concentration, filtration has minimal impact. Research indicates that changes in peptide concentration after filtration are not significant enough to affect practical use, and in some cases, a slight increase in concentration was observed, possibly due to the filter retaining water while allowing peptides to pass through However, the loss is primarily volumetric rather than due to peptide degradation or binding.
Additionally, the brand and quality of the filter matter. Some generic filters may have higher holdup volumes than trusted brands like Tisch, which are known for consistent performance For optimal recovery, especially in low-level peptide analysis, high-quality filters such as Agilent Captiva Premium PES syringe filters have demonstrated superior recovery rates (>97%) and reduced column backpressure
In summary, to minimize peptide loss, use a 4 mm PES syringe filter for volumes up to 4 mL, ensure the filter is sterile and low-protein binding, and prefer reputable brands to avoid variability in holdup volume
Edit: Grammer
