MS CA Syringe Filter

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Features

• Naturally hydrophilic membrane filter
• Low protein binding: suitable for aqueous protein solutions
• Nitrate free: suitable for groundwater filtration
• Quiet uniform pore size structure
• Extensive pore size specification
• Cell retention and particle collection

Applications

• Filtration for aqueous sample and some organic solvents
• Cell Retention for liquid
• Light Scattering Measurement
• Sterilization

Technical Parameters

FAQ

1.How to select a syringe filter based on the membrane material？

Nylon Syringe Filter---Low extractable. Filtration of mixed solvents and solvents, HPCL samples.
PES Syringe Filter---High flow rate. Filtration of tissue culture media.
PVDF Syringe Filter---Low protein binding. Compatible with protein solutions and mild organic solutions.
PTFE Syringe Filter---Maximum chemical resistance. Filtration of mixed solvents and solvents.
PP Syringe Filter---Broad range of pore sizes. Prefiltration and solvent filtration.
GF Syringe Filter --- Water quality analysis.

2.What is the difference between hydrophilic and hydrophobic membranes? How to select the correct membrane for my solvent?

The fundamental difference lies in the surface chemical properties (hydrophilic/hydrophobic groups, roughness, etc.), leading to differences in water wettability, protein adsorption, and application areas.
Hydrophilic membranes are generally used for most aqueous liquid filtration. They can often also be used for organic solvent/water mixtures.
Hydrophobic membranes are typically used for pure organic solvents, corrosive liquids, and gas filtration.

3.Under what circumstances can non-sterile filters be chosen? Which applications require sterile filters?

The primary criterion for choosing sterile vs. non-sterile filters is whether a biological system is involved.
Sterile Filters: Media preparation and dispensing, sterilization of reagents like serum and trypsin, microbiology experiments (sterilization of antibiotic, vitamin solutions), molecular biology for filtering enzymes/nucleic acid solutions for sensitive experiments, sterilization filtration for injections/eye drops, cold sterilization of food products like beer, wine, juice.
Non-sterile Filters: HPLC sample preparation, environmental water samples, pretreatment of chemical reagents, mobile phase filtration, filtration of non-critical solutions.

4.What is the difference in filtration performance between welded and encapsulated filter designs?

For filters of the same specification, the welded filter has a larger effective filtration area, resulting in relatively better filtration performance.

•  All MS 4mm filters are welded filters.
• 13mm encapsulated filter effective filtration area: 0.92 cm²; Welded version: 1.09 cm².
• 25mm encapsulated filter effective filtration area: 2.98 cm²; Welded version: 4.08 cm².

5.What are the potential causes of cracking in filters during use?

1)Incompatibility between the housing and the solvent, e.g., using an MBS housing to filter strong polar solvents.
2)Excessive operating pressure, exceeding the filter's safe working pressure (87 Psi / 0.6 MPa).
3)Special sample properties leading to poor product flux, causing pressure buildup.​

6.In HPLC analysis, why is it necessary to filter both samples and mobile phases?

1)To protect the chromatographic instrument and extend the column's lifespan.
2)To ensure the accuracy and reproducibility of analytical results.

7.When selecting a chromatographic filter, how should one choose the appropriate diameter and membrane material based on sample volume and properties (e.g., solution type)?

When selecting a chromatographic filter, a comprehensive assessment considering sample volume, sample composition, and impurity content is required. Typical filtration volumes: 4mm filter: 1ml, 13mm filter: 1-10ml, 25mm filter: 10-100ml, 30mm filter: <120ml. If impurity content is high, a prefilter is usually needed. Membrane material selection should be based on customer application requirements and membrane performance.

8.Does the product comply with relevant pharmacopoeias or industry standards?

Our filters currently hold the following certifications: CNAS certification, ISO 13485 certification, ISO 9001 certification, CE marking, FDA certification (membrane only). 

9.What is the basis for selecting pore size (0.1μm vs. 0.22μm vs. 0.45μm)?

0.1μm: Mycoplasma/virus removal, or pretreatment before ultrafiltration.
0.22μm: Used for sterilization, removing all bacteria (but not mycoplasma or viruses).
0.45μm: Used for clarification, removing general particulates and most bacteria.

10.What is the significance of "low protein adsorption" filter membranes?

Purification of valuable proteins requires filters to remove impurities. If the membrane adsorbs protein, protein will adhere to the membrane post-filtration, reducing the protein content in the final filtrate and affecting recovery yield.

11.What is the purpose of a prefilter layer? When should a filter with a prefilter be used? What is the main material and typical pore size?

The prefilter layer acts as a coarse screen, reducing direct contact of particulates in the liquid with the final membrane, thereby increasing the filtration capacity per filter. It is generally used for clarifying solutions with high particulate content. The main material is usually binder-free glass fiber. Pore size is generally >1μm, selected based on the final application.

12.How to verify that the selected filter does not adsorb or leach substances into the sample?

Requires a customized target analyte adsorption test protocol based on the customer's specific sample, detection targets, and requirements. Generally, our validation center can undertake this testing. (Our hydrophilic PVDF and PES membranes have low protein adsorption).

13.Which brands of syringes are compatible with the filters? Are there any compatibility issues?

Standard filters and standard syringes use standard Luer fittings and are basically universally compatible. Generally, there are no compatibility issues.

14.What is the recommended syringe plunger pressure? What are the consequences of excessive force?

10-20 psi is optimal. Excessive force can cause the membrane to compress against the flow channel, leading to poor flow rate, or even housing rupture.

15.What could be the reasons for encountering excessive resistance or inability to push during filtration?

1)Incompatibility between the filter membrane and the filtrate.
2)Shallow flow channels in the lower housing.

16.When filtering protein samples, flux decreases rapidly. How to improve this?

Filter design perspective: Deepen flow channels, but effect is limited.
Membrane perspective: Increase porosity.
Application perspective: Select appropriate membrane pore size and material.

17.After filtration, white precipitate appears in the filter housing or collection container. What could it be?

It could be dissolution of the filter membrane due to incompatibility with the reagent.

18.Can syringe filter be reused?

No, they should not be reused. After filtering a solution, some pores become blocked. Performance is poor upon reuse. Reuse can cause cross-contamination of solutions. 

19.How should used syringe filters be disposed of?

Dispose of according to usage. Filters used for routine filtration (no contact with microorganisms) have no special requirements. Filters used for filtering bacterial solutions should be sterilized before disposal. If used for filtering toxic or corrosive solutions, handle as hazardous chemical waste according to laboratory protocols.

20.Is integrity testing performed on every filter batch? What are the release standards?

Yes, integrity is typically assessed via bubble point testing. Release standards vary according to the membrane material.(Bubble point is an important indicator of filter integrity, but a passing bubble point does not necessarily guarantee bacterial retention.)

21.What is bubble point testing? Can customers perform bubble point testing on used filters themselves?

Bubble point is the minimum pressure required to force the first bubble of gas through a liquid-wetted membrane, serving as an important indicator of filter integrity. It depends on the customer's experimental conditions; if they have the corresponding equipment, they can perform it.

22.What is the shelf life of the products? Is there a difference between sterile and non-sterile products?

Sterile Filters: 3 years; beyond 3 years, there is a risk of microbial contamination, not recommended for use.
Non-sterile Filters: Recommended 5 years; can be used beyond 5 years if performance shows no significant degradation.

23.How to store filters correctly? What are the storage environment requirements (temperature, humidity)?

Store in a cool, dry, clean environment. Ideal temperature range: 10-30°C. Humidity <70%. Sterile filters should not be stored in high humidity environments.

24.How to confirm the purchased product is genuine/original?

Verify via the production batch number, which is unique. 

25.How is consistency between product batches ensured?

Controlled through standards. Filter products have release specifications. Quality control checks against these specs determine release. Performance variation between batches is normal, but all products released must meet the enterprise standards.

26.What technical support can be provided if there are questions about product performance?

Can be provided based on customer needs, such as product TDS (Technical Data Sheet), various test data, and test reports.

27.Can custom services be provided?

Custom services can be provided for products meeting the minimum order quantity (MOQ) requirement.

28.When used for cell culture, do filters leach substances toxic to cells?

Products passing USP <87>, USP <88> tests generally show no significant cytotoxicity. However, production processes must be well-controlled to avoid introducing exogenous cytotoxic substances, such as residual disinfectants from the production environment.

29.Chromatography Filters: Black spots found in 30MM All pure filters/Allpure filter black spot foreign matter 

Encapsulation edge: Impurities present in the PP material, or introduced from the injection molding machine barrel/piping during encapsulation molding.
On housing: Residue from the printing process.
On membrane: Introduced airborne fibers/particles.

(Manual inspection is conducted before shipment to prevent such filters from leaving the factory.)

30.How to select a filter when filtering viscous samples or samples with high particulate load?

Choose filters with a prefilter or high-throughput filters. If particulate content is extremely high, preliminary coarse filtration is recommended to remove some large particles.

31.Is pre-wetting necessary before use? How to correctly wet a hydrophobic membrane filter?

Normally, pre-wetting is not recommended. Material and solvent selection should ensure the surface tension of the target solvent is lower than the critical surface tension of the membrane. If wetting is necessary under special circumstances, generally use the liquid to be filtered for wetting.