Clarification of Samples (1-100 mL) in an Acrodisc® Syringe Filter 2.5.4

Larger-volume samples (10-50 mL) can be clarified by MF in an Acrodisc syringe filter. MF filters are available in 0.1, 0.2, 0.45, 0.8, 1.2, and 5.0 μm pore sizes with:

• GHP hydrophilic modified polypropylene membrane.
• GxF glass fiber prefilter plus GHP combination filter to handle viscous or heavy particle containing samples (GHP plus GHP/GxF only available in 0.2 and 0.45 μm pore sizes).
• Hydrophilic low protein binding Supor® PES (polyethersulfone) membrane.

In the case of the Supor PES membranes, 0.8/0.2 μm and 1.2/0.45 μm membrane combinations are also available for small pore size filtration of higher viscosity samples, such as serum or plasma with cryoprecipitate present. The Acrodisc MF syringe filter properties are summarized in Table 2.59 for 13, 25, and 32 mm diameter devices.

Table 2.59

Properties of the Acrodisc® MF Syringe Filter

Specification	Parameter
Membranes     GHP     Supor®     GxF Prefilter	GHP is a hydrophilic polypropylene PES Hydrophilic polyethersulfone (PES) Binder free borosilicate glass fiber
Device	Polypropylene
Effective Filtration Area     13 mm .     25 mm .     32 mm .	1.0 cm2  3.9 cm2  5.8 cm2
Pore Size     HP     Supor PES	0.2, 0.45 μm 0.1, 0.2, 0.45, 0.8, 1.2, 5.0 μm
Sample Volume     13 mm      25 mm	< 10 mL < 50 mL
Hold-up Volumes     13 mm      25 mm      25 mm plus GxF	0.014-0.028 mL 0.100-0.125 mL 0.100-0.200 mL
Maximum Temperature	55 °C
Maximum Pressure Limit     13 mm 6.3 bar      25 mm 4.1 bar      32 mm	(630 kPa, 92 psi) (410 kPa, 60 psi) 5.2 bar (520 kPa, 75 psi)
Typical Water Flow Rate (mL/min)     13 mm (0.2 μm) at 10-45 psi      13 mm (0.45 μm)      25 mm (0.1 μm) at 30-45 psi      25 mm (0.2 μm)      25 mm (0.45 μm)      25 mm (0.8 μm) 700     25 mm (1.2 μm) 1700     25 mm (0.8/0.2 μm)     32 mm (0.1 μm) at 45 psi     32 mm (0.2 μm)     32 mm (0.45 μm)     32 mm (1.2 μm) 1     32 mm (5.0 μm)     32 mm (0.8/0.2 μm)	17-35 (PES) 28-35 (PES) 35 (PES)-175 175 (PES)-195 195-300 (PES) 700 1700 145 100 490 700 1700 1750 440
Inlet/Outlet Connectors     13 mm      25 mm  outlet     32 mm	Female inlet, luer-lok minispike outlet Female luer-lok inlet, male slip luer Female luer-lok inlet, male slip luer outlet

Application Guidelines for Clarification of Samples (1-100 mL) in an Acrodisc® Syringe Filter

Syringe adapted filtration devices, such as Acrodisc syringe filters, have a wide variety of applications and are key to some analytical and screening processes in biosciences. Typical applications of Acrodisc MF syringe filter clarification in Proteomics include:

• Clarification of dilute (1:4) plasma or serum samples prior to abundant protein depletion to remove cryoprecipitates generated when thawing samples.
• Prefiltration of samples prior to injection into an HPLC system to remove fine colloidal material that could block a small particle diameter column.
• Filtration of buffers and solvents used in liquid chromatography and HPLC.
• Filter sterilization of components or additives for cell culture that are heat labile.
• Clarification of reagents and stains used in proteomics.

Protocol for Clarification of Samples (1-100 mL) in an Acrodisc Syringe Filter

A. Materials Required

1. Acrodisc syringe filter with MF membranes. For specifications, see Table 2.59.
2. Empty syringes (10-60 mL volume)
3. High purity water or buffer, such as phosphate buffered saline (PBS)

B. MF Acrodisc Filtration in Syringe Adapted Format

1. Before filling the syringe with sample, draw approximately 1 mL of air into the device. This will allow the air to follow the sample out of the syringe. This “air purge” minimizes fluid retention in the filter device.
2. Fill the syringe with the solution to be filtered.
   Tip: Use of syringes smaller than 10 mL can generate excessive pressure on the filter, which may exceed maximum operating pressure.
3. Holding the filter device in one hand and the filled syringe in the other, secure (without excessive force) the filled syringe to the filter device with a twisting motion.
4. Apply gentle pressure to begin filtration. (A gentle pressure helps assure maximum throughput.)
   Tip: As the filter removes particulate, filtration will become more difficult (the syringe plunger will be harder to push), and pressure will rapidly increase on the filter. Change filters when resistance becomes excessive. Failure to change filter may result in housing rupture, which results in particulate contaminating the filtrate.

Tip: These filters are for SINGLE USE ONLY. 

Application Data for Clarification of Samples (1-100 mL) in an Acrodisc Syringe Filter

The modified polypropylene GHP membrane exhibits very low DNA and protein non-specific binding. An example of a comparison of macromolecule binding to GHP and a nylon Biodyne® B membrane are summarized in Figure 2.55. The data clearly shows very low DNA or protein binding to the hydrophilic modified polypropylene membrane. Low protein binding also leads to high recovery of protein in the dilute filtrates. An example of such a study with a Supor® 0.2 μm PES membrane is summarized in Figure 2.56, with a control of Posidyne® nylon membrane showing poor recovery.

Figure 2.55

Hydrophilic Modified Polypropylene (GHP) Membrane Is Extremely Low in DNA and Protein Non-Specific Binding

¹²⁵I-labeled BSA (1.6 μg) or 32P-labeled DNA (500 ng) were diluted to 5 mL in PBS (BSA) or Tris-EDTA buffer pH 8.0 (DNA) and filtered through a 13 mm disc of the indicated membrane. Filtration was carried out using a 10 mL syringe at a flow rate of 1.0 mL/min. Binding was determined by comparing the amount of radioactivity remaining in the membrane (triplicate) to the activity of the starting material by placing the disc or solution directly into a scintillation cocktail and counting in a scintillation counter. Biodyne® B membrane is designed for biomolecules binding and was used as a positive control.

Figure 2.56

Protein Passage Through Supor® PES vs. Posidyne® Nylon Filter Membranes

The addition of a 0.8 μm PES prefilter to a 0.2 μm PES sterilization membrane considerably improves throughput with viscous, particulate-laden or high protein content solutions, such as serum or plasma. The PES 0.2 μm membrane shows high throughput for filtration of high viscosity samples, such as Dextran, Trypticase Soy Broth, and BSA. When a prefilter is also present, further improvement in filtration throughput can be seen. A comparison of filtration of bovine serum or a bacterial culture with a 0.8/0.2 μm Supor® PES Acrodisc® syringe filter is summarized in Figure 2.57. The prefilter considerably extends the filter life of these samples beyond 10-20 seconds when the 0.2 μm PES filter reaches a plateau of throughput.  

Figure 2.57

Increased Filtration Throughput with a 0.8/0.2 μm Supor PES Acrodisc Syringe Filter Compared to a Single 0.2 μm Membrane

Acrodisc 0.2 μm and Acrodisc PF 0.8/0.2 μm Supor syringe filters were challenged with Panel A, calf serum or Panel B, a bacterial culture (B. diminuta at 107 cfu/mL) at a constant pressure of 1.4 bar (140 kPa, 20 psi).

Ordering Information for Clarification of Samples (1-100 mL) in an Acrodisc® Syringe Filter

Acrodisc Syringe Filters with GHP Membrane, 13 mm

Part Number	Description	Pkg
4554	0.2 μm,minispike outlet	100/pkg, 300/cs
4567	0.2 μm,minispike outlet	1000/pkg
4556	0.45 μm,minispike outlet	100/pkg, 300/cs
4563	0.45 μm,minispike outlet	1000/pkg

Acrodisc PSF Syringe Filters with GHP Membrane, 25 mm

Part Number	Description	Pkg
AP-4564	0.2 μm	50/pkg, 200/cs
AP-4566	0.2 µm	1000/pkg
AP-4560	0.45 µm	50/pkg, 200/cs
AP-4562	0.45 μm	1000/pkg

Acrodisc PSF GxF Syringe Filters with GHP Membrane, 25 mm

Part Number	Description	Pkg
AP-4307	GxF/0.2 μm	50/pkg, 200/cs
AP-4306	GxF/0.2 μm	1000/pkg
AP-4559	GxF/0.45 μm	50/pkg, 200/cs
AP-4558	GxF/0.45 μm	1000/pkg

Acrodisc® Syringe Filters with Supor® Membrane, Non-sterile

Part Number	Description	Pkg
4506	0.2 μm, 25 mm, modified acrylic housing	1000/pkg
4655	0.2 μm, 32 mm, modified acrylic housing	1000/pkg
4508	0.45 μm, 25 mm, modified acrylic housing	1000/pkg
4653	0.45μm, 32 mm, modified acrylic housing	1000/pkg
4509	0.8 μm, 25 mm, modified acrylic housing	1000/pkg
4504	0.8/ 0.2 μm, 25 mm, modified acrylic housing	1000/pkg
4659	0.8/0.2 μm, 32 mm, modified acrylic housing	1000/pkg
4660	1.2 μm, 32mm, modified acrylic housing	1000/pkg
4661	1.2/0.45 μm, 32 mm, modified acrylic housing	1000/pkg
4662	5 μm, 32 mm, modified acrylic housing	1000/pkg

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