These membranes are characterized by a smoother and more uniform surface than pure nitrocellulose filters. Also, the color contrast provided by the filter surface facilitates particle detection and minimizes eye fatigue. The ME range has a lower cellulose acetate content compared to the WME range of membranes.
Eased counting process
In microbiological colony counting procedures, the color contrast between the surface and the colonies facilitates the counting process. Plain or gridded
Many microbiological techniques include colony counting after incubation as the standard method of quantification. Whatman gridded filters have clearly defined grid lines spaced at 3.1 mm or 5 mm intervals. The special ink used is nontoxic and completely free from bacterial growth inhibitors. Whatman black mixed cellulose esters are available plain for automatic colony counting applications, as well as gridded to assist in manual counting procedures. Black membranes provide contrast between residue or cell colors and the filter without having to counter-stain the membrane.
Sterile filters
Features and benefits
For those laboratories preferring to use membranes sterilized by autoclaving for microbiological work, Whatman provides black gridded membranes in packs with pads ready for laboratory autoclaving.
Applications
The membrane is particularly effective in applications requiring higher flow rates and larger volume filtration including clarification or sterilization of aqueous solutions, particulate analysis and removal, air monitoring and microbial analysis. Other applications include:
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Burst strength | > 10 psi |
Weight | 4.3 to 5.0 mg/cm2 |
Maximum service temperature | 130°C |
Porosity | 74 to 77% |
Steam autoclavable | Yes |
Solvent resistancy | Medium |
Protein binding | Medium |
Pore size (µm) (membrane type) |
Thickness (µm) |
Water flow rate Δp = 0.9 bar (s/100 ml/12.5 cm2) |
Air flow rate Δp = 3 mbar (s/100 ml) |
Bubble point (bar) |
WME product range | 140 | - | - | - |
ME product range | ||||
0.2 (ME 24) | 135 | 20 | - | 3.7 |
0.45 (ME 25) | 145 | 12.5 | - | 2.8 |
0.6 (ME 26) | 135 | 4.8 | 21 | 1.9 |
0.8 (ME 27) | 140 | 2.8 | 11.6 | 1.3 |
1.2 (ME 28) | 140 | 2 | 9.3 | 0.8 |
3 (ME 29) | 150 | 1.2 | 6.7 | 0.7 |
Catalog Number | Description | |
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7140-104 | Mixed cellulose ester circles (WME), 0.45 µm, 47 mm, 100/pk | |
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10401706 | Mixed cellulose ester circles (ME 24), 0.2 µm, 25 mm, 100/pk | |
10401712 | Mixed cellulose ester circles (ME 24), 0.2 µm, 47 mm, 100/pk | |
10401770 | Mixed cellulose ester circles (ME 24), sterile, 0.2 µm, 47 mm, 100/pk | |
10401714 | Mixed cellulose ester circles (ME 24), 0.2 µm, 50 mm, 100/pk | |
10401772 | Mixed cellulose ester circles (ME 24), sterile, 0.2 µm, 50 mm, 100/pk | |
10401721 | Mixed cellulose ester circles (ME 24), 0.2 µm, 100 mm, 50/pk | |
10401726 | Mixed cellulose ester circles (ME 24), 0.2 µm, 110 mm, 50/pk | |
10401731 | Mixed cellulose ester circles (ME 24), 0.2 µm, 142 mm, 25/pk | |
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10401606 | Mixed cellulose ester circles (ME 25), 0.45 µm, 25 mm, 100/pk | |
10401612 | Mixed cellulose ester circles (ME 25), 0.45 µm, 47 mm, 100/pk | |
10401670 | Mixed cellulose ester circles (ME 25), sterile, 0.45 µm, 47 mm, 100/pk | |
10401614 | Mixed cellulose ester circles (ME 25), 0.45 µm, 50 mm, 100/pk | |
10401662 | Mixed cellulose ester circles (ME 25), without interleaving paper, 0.45 µm, 50 mm, 100/pk | |
10401672 | Mixed cellulose ester circles (ME 25), sterile, 0.45 µm, 50 mm, 100/pk | |
10401618 | Mixed cellulose ester circles (ME 25), 0.45 µm, 90 mm, 50/pk | |
10401621 | Mixed cellulose ester circles (ME 25), 0.45 µm, 100 mm, 50/pk | |
10401626 | Mixed cellulose ester circles (ME 25), 0.45 µm, 110 mm, 50/pk | |
10401631 | Mixed cellulose ester circles (ME 25), 0.45 µm, 142 mm, 25/pk | |
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10401506 | Mixed cellulose ester circles (ME 26), 0.6 µm, 25 mm, 100/pk | |
10401512 | Mixed cellulose ester circles (ME 26), 0.6 µm, 47 mm, 100/pk | |
10401514 | Mixed cellulose ester circles (ME 26), 0.6 µm, 50 mm, 100/pk | |
10401521 | Mixed cellulose ester circles (ME 26), 0.6 µm, 100 mm, 50/pk | |
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10400906 | Mixed cellulose ester circles (ME 27), 0.8 µm, 25 mm, 100/pk | |
10400909 | Mixed cellulose ester circles (ME 27), 0.8 µm, 37 mm, 100/pk | |
10400912 | Mixed cellulose ester circles (ME 27), 0.8 µm, 47 mm, 100/pk | |
10400970 | Mixed cellulose ester circles (ME 27), sterile, 0.8 µm, 47 mm, 100/pk | |
10400914 | Mixed cellulose ester circles (ME 27), 0.8 µm, 50 mm, 100/pk | |
10400921 | Mixed cellulose ester circles (ME 27), 0.8 µm, 100 mm, 50/pk | |
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10400806 | Mixed cellulose ester circles (ME 28), 1.2 µm, 25 mm, 100/pk | |
10400812 | Mixed cellulose ester circles (ME 28), 1.2 µm, 47 mm, 100/pk | |
10400814 | Mixed cellulose ester circles (ME 28), 1.2 µm, 50 mm, 100/pk | |
10400821 | Mixed cellulose ester circles (ME 28), 1.2 µm, 100 mm, 50/pk | |
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10400706 | Mixed cellulose ester circles (ME 28), 3 µm, 25 mm, 100/pk | |
10400712 | Mixed cellulose ester circles (ME 28), 3 µm, 47 mm, 100/pk | |
10400714 | Mixed cellulose ester circles (ME 28), 3 µm, 50 mm, 100/pk | |
10400772 | Mixed cellulose ester circles (ME 28), sterile, 3 µm, 50 mm, 100/pk | |
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10406970 | Mixed cellulose ester circles (ME 24), white/black grid 3.1 mm, sterile 0.2 µm, 47 mm, 100/pk | |
10406914 | Mixed cellulose ester circles (ME 24), white/black grid 3.1 mm, 0.2 µm, 50 mm, 100/pk | |
10406972 | Mixed cellulose ester circles (ME 24), white/black grid 3.1 mm, sterile, 0.2 µm, 50 mm, 100/pk | |
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10406812 | Mixed cellulose ester circles (ME 25), white/black grid 3.1 mm, 0.45 µm, 47 mm, 100/pk | |
10407970 | Mixed cellulose ester circles (ME 25), white/black grid 3.1 mm, sterile, 0.45 µm, 47 mm, 100/pk | |
10406871 | Mixed cellulose ester circles (ME 25), white/black grid 3.1 mm, sterile, 0.45 µm, 47 mm, 1000/pk | |
10406512 | Mixed cellulose ester circles (ME 25), white/black grid 5 mm, 0.45 µm, 47 mm, 100/pk | |
10409712 | Mixed cellulose ester circles (ME 25), black/white grid 3.1 mm, 0.45 µm, 47 mm, 100/pk | |
10409770 | Mixed cellulose ester circles (ME 25), black/white grid 3.1 mm, sterile, 0.45 µm, 47 mm, 100/pk | |
10409771 | Mixed cellulose ester circles (ME 25), black/white grid 3.1 mm, sterile, 0.45 µm, 47 mm, 1000/pk | |
10409414 | Mixed cellulose ester circles (ME 25), green/black grid 3.1 mm, 0.45 µm, 47 mm, 1000/pk | |
10406814 | Mixed cellulose ester circles (ME 25), white/black grid 3.1 mm, 0.45 µm, 50 mm, 100/pk | |
10406862 | Mixed cellulose ester circles (ME 25), white/black grid 3.1 mm, without interleaving paper, 0.45 µm, 50 mm, 100/pk | |
10406873 | Mixed cellulose ester circles (ME 25), white/black grid 3.1 mm, sterile, 0.45 µm, 50 mm, 1000/pk | |
10406514 | Mixed cellulose ester circles (ME 25), white/black grid 5 mm, 0.45 µm, 50 mm, 100/pk | |
10406572 | Mixed cellulose ester circles (ME 25), white/black grid 5 mm, sterile, 0.45 µm, 50 mm, 100/pk | |
10406562 | Mixed cellulose ester circles (ME 25), white/black grid 5 mm, without interleaving paper, 0.45 µm, 50 mm, 100/pk | |
10409714 | Mixed cellulose ester circles (ME 25), black/white grid 3.1 mm, 0.45 µm, 50 mm, 100/pk | |
10409772 | Mixed cellulose ester circles (ME 25), black/white grid 3.1 mm, sterile, 0.45 µm, 50 mm, 100/pk | |
10409462 | Mixed cellulose ester circles (ME 25), green/black grid 3.1 mm, without interleaving paper, Sterile, 0.45 µm, 50 mm, 100/pk | |
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10409814 | Mixed cellulose ester circles (ME 26), black/white grid 3.1 mm, 0.6 µm, 50 mm, 100/pk | |
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10408970 | Mixed cellulose ester circles (ME 27) white/black grid 3.1mm, sterile, 0.8 µm, 47 mm, 100/pk | |
10409970 | Mixed cellulose ester circles (ME 27), white/black grid 3.1 mm with pad, sterile, 0.8 µm, 47 mm, 100/pk | |
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7187-114 | Mixed cellulose ester circles (WME), white/black grid 3.1 mm, 0.2 µm, 47 mm, 100/pk | |
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7141-002 | Mixed cellulose ester circles (WME), white/black grid 3.1 mm, 0.45 µm, 25 mm, 100/pk | |
7141-004 | Mixed cellulose ester circles (WME), white/black grid 3.1 mm, 0.45 µm, 47 mm, 100/pk | |
7141-104 | Mixed cellulose ester circles (WME), white/black grid 3.1 mm, sterile, 0.45 µm, 47 mm, 100/pk | |
7141-114 | Mixed cellulose ester circles (WME), white/black grid 3.1 mm, sterile, without pad, 0.45 µm, 47 mm, 100/pk | |
7141-124 | Mixed cellulose ester circles (WME), white/black grid 3.1 mm, sterile, 0.45 µm, 47 mm , 200/pk | |
7141-154 | Mixed cellulose ester circles (WME), white/black grid 3.1 mm, sterile, without pad, 0.45 µm, 47 mm, 1000/pk | |
7141-204 | Mixed cellulose ester circles (WME), white/black grid 3.1 mm, autoclave pack, sterile, 0.45 µm, 47 mm, 100/pk | |
7153-004 | Mixed cellulose ester circles (WME), black/white grid 3.1 mm, 0.45 µm, 47 mm, 100/pk | |
7153-104 | Mixed cellulose ester circles (WME), black/white grid 3.1 mm, sterile, 0.45 µm, 47 mm, 100/pk | |
7155-004 | Mixed cellulose ester circles (WME), green/black grid 3.1 mm, sterile, 0.45 µm, 47 mm, 100/pk | |
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7148-002 | Mixed cellulose ester circles (WME), white/black grid 3.1 mm, 0.8 µm, 25 mm, 100/pk |
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