How we evaluate syringe filters
New product launch
Introducing Peptide Test Syringe Filters
Why we launched Peptide Test Filters
We’re excited to announce the launch of Peptide Test branded syringe filters.
Syringe filters are one of those deceptively simple items that quietly determine how smooth and predictable a workflow feels. When they are great, nobody notices. When they are inconsistent, you notice fast. That’s why we decided to treat syringe filters like a core product category, not an accessory.
This post explains what we’re launching, why we made the change, and what we learned along the way.
Introducing Peptide Test Filters
We are standardizing on a new Peptide Test branded OEM syringe filter as our primary offering going forward. This is the result of a long sourcing and testing process where we evaluated a wide field of manufacturers and models and selected a partner whose quality and finish stood out enough to justify a clean transition.
This is a product launch, not a retroactive criticism of what we previously carried. We sold a lot of Tisch Scientific filters because they were a dependable option for many customers.
Why we took a fresh look at filters
As Peptide Test has grown, we’ve become more intentional about understanding upstream manufacturing and controlling the details that affect consistency. In filtration, those details live in places you do not always see on a product listing.
Lot consistency, packaging integrity, housing quality, membrane structure, and basic fit and finish all influence performance and confidence. We wanted to be sure that what we stock reflects the best standard we can reasonably source, with a supply chain we can stand behind long term.
The upstream manufacturing context
During our sourcing process, we learned that the Tisch Scientific syringe filters we had been supplying are manufactured by Membrane Solutions.
OEM and private labeling are extremely common in this category. Many reputable brands sell filters produced by large membrane manufacturers. That model is normal, and it can produce solid products.
Once we understood the upstream origin, we had a straightforward option. We could negotiate a direct OEM arrangement and essentially keep the same upstream supply path under our own label. We did negotiate an OEM arrangement with Membrane Solutions, but ultimately decided not to proceed. At that point, simply putting our label on a widely distributed OEM filter wasn’t the end goal. We wanted to be confident we were carrying the best filter we could source and not simply something that was ubiquitous on Amazon and Ebay.
If you specifically want a Membrane Solutions manufactured filter, they are widely available through many retail channels, and you can often find those products directly without needing us as an intermediary brand in the middle.
What testing and evaluation we did
Before launching this new filter, we evaluated multiple options and compared them side by side against the product we had been supplying.
Our process began with third-party Scanning Electron Microscopy (SEM) so we could directly visually examine membrane structure across candidate filters. All images were captured at identical settings and resolution (20kV, x2,500, 10 µm scale bar, SEI are shown below but we evaluated at many different resolutions) to allow true like-for-like comparison. This initial screening allowed us to confirm which filters demonstrated consistent, properly formed porous membrane architecture before advancing them to further evaluation.
The SEM review was extremely revealing. At the same microscopic resolution, some low-cost marketplace filters did not visually resemble high-quality PES or PTFE membranes. In several cases, the membrane surface appeared more woven or fibrous rather than exhibiting the uniform porous morphology expected of properly manufactured membranes. In a subset of samples we also observed large structural gaps at the same resolution, which can indicate poor materials or inconsistent membrane formation. While SEM alone does not determine performance, it proved to be an effective first-pass quality screen that allowed us to eliminate candidates that did not meet our structural expectations.
Only filters that demonstrated consistent pore structure under SEM were advanced to the next phase of review. For those candidates, we evaluated physical construction and finish, packaging integrity and overall manufacturing consistency. We also reviewed manufacturer Certificates of Analysis to assess key quality indicators such as membrane material verification, pore size specification, burst/bubble point or integrity data, extractables/endotoxin where provided, and lot-level QC documentation and traceability.
When we landed on a prefered candidate, sterility performance was also confirmed. Microbial retention of the 0.22 µm PES membranes was verified through a controlled bacterial challenge using Brevundimonas diminuta. Post-filtration culture analysis demonstrated complete retention across tested units, confirming the membrane’s ability to remove microorganisms and effectively reduce bioburden under normal operating conditions. This confirms that the membrane meets established expectations for 0.22 µm microbial removal and supports its use in aseptic filtration workflows. Brevundimonas diminuta is 0.3 µm on average so it is a great test for filter performance.
All SEM images shown below were captured at the same settings and resolution so morphology differences can be evaluated directly without zoom or capture variability.
We are deliberately not publishing a public scoreboard or making performance claims about specific brands because filtration performance depends heavily on sample type, technique, and conditions. A simplistic ranking is rarely fair or useful, and it can create the wrong impression about products that many customers have used successfully.
What we looked for in a long term OEM partner
We are not naming individual upstream manufacturers in this post. The filter we now carry is produced through a dedicated OEM relationship with a manufacturer whose core business is producing chromatography and laboratory consumables at scale, with an emphasis on quality systems and process control.
Our OEM partner maintains an ISO 9001:2015 quality management system. Beyond certification, what mattered to us was the operational posture behind it. We prioritized manufacturers that demonstrate structured QC practices, documented processes, lot traceability, and a production environment designed for consistent output.
We also preferred partners with meaningful in house testing capability and the ability to support ongoing quality oversight as volume grows. In short, we wanted a supply chain we can rely on long term, with the documentation discipline and manufacturing consistency that matches our standards.
SEM gallery, 20kV, x2,500, 10µm
Closing
This launch reflects a simple idea. We want every product we carry to earn its spot. That means doing the legwork, testing broadly, and making changes when we find something we genuinely believe is better.
We appreciate your support, and we appreciate the questions that pushed us to go deeper on filtration quality than most sellers ever do.
If you have questions about the new Peptide Test syringe filters or want help choosing the right option for your workflow, reach out anytime.
Image note: All SEM images on this page are presented at 20kV, x2,500, and a 10µm scale bar using SEI mode for direct visual comparison.
Peptide Filtering Basics (Written Instructions)
Learn how to safely reconstitute lyophilized peptides and filter them with a syringe filter using a clear, written step-by-step guide. This video walks you through the full process for sterile and accurate peptide preparation in a research setting.
Peptide Filtering Basics
Demonstration on how to reconstitute a lyophilized peptide vial and filter it using a syringe, reducing bioburden for laboratory research use.
Filtering Demonstration
This quick demo shows what the process aims to achieve. Using a sterile 0.22µm 4mm PES syringe filter, we remove activated carbon from distilled water to simulate how bioburden is removed from peptides during reconstitution. Perfect for beginners in lab prep or peptide research.
Filtering Demo Continued
Follow-up to syringe filtering demo; additional tips, observations, and troubleshooting from the process of filtering multiple reconstituted peptide vials. Learn what to expect during real-world lab prep.
4mm Filter Capacity Test
Demonstration of a realistic syringe filtering scenario by reconstituting 4 vials, each with 1mL of solution. This practical guide offers insight into actual lab prep conditions for peptide reconstitution and sterile filtration using syringe filters.
4mm Filter Capacity to Failure
This video tests the volumetric capacity of a 4mm 0.22µm sterile syringe filter. To simulate mannitol commonly found in lyophilized peptide vials, we used cane sugar at a concentration of 0.5g per 10mL. A useful reference for anyone working with peptide filtration and lab preparation techniques.
How Much Bac Water will fit?
Find out exactly how much bacteriostatic water you can add to 2mL and 3mL glass vials. This quick guide helps you avoid overfilling, ideal for research use.
Group Testing Procedure
Save money on peptide testing: Our group testing option lets you share costs with others while still receiving fast, accurate, and confidential results. Perfect for those who want reliable peptide testing without breaking the bank.