Amicon
®
Ultra-2 Centrifugal Filter Devices
4
Performance - Protein Concentration
Flow Rate
Factors affecting flow rate include sample concentration, starting vol ume, chemical nature of solute, relative centrifugal force,
centrifuge rotor angle, membrane type, and temperature. Figures 1 and 2 and Tables 2 and 3 can be used to estimate the time
required to achieve a given volume of filtrate or concentrate for a variety of protein markers. A typical spin time for a 2 mL sample
in a fixed angle rotor is approximately 10 to 60 minutes (depending on device nominal molecular weight limit). While most of
the sample is filtered in the first 10 to 20 minutes of centrifugation, the lowest concentrate volume (30–70 μL) is reached after
spinning for 10 to 60 minutes.
Figure 1. Typical Filtrate Volume vs. Spin Time for Amicon
®
Ultra-2 Device, Swinging Bucket Rotor
0
0.5
1
1.5
2
0
10
20
30
40
50
60
3K
10K
30K
50K
100K
Filtr
ate
Volume
(mL)
Spin time (min)
0
0.5
1
1.5
2
0
10
20
30
40
50
60
3K
10K
30K
50K
100K
Spin time (min)
Filtr
ate
Volume
(mL)
Spin conditions: Swinging bucket rotor, 4,000 × g, room temperature, 2 mL starting volume.
Protein markers used: Cytochrome c for 3K and 10K, BSA for 30K and 50K, and IgG for 100K, n=8.
Figure 2. Typical Filtrate Volume vs. Spin Time for Amicon
®
Ultra-2 Device, Fixed Angle Rotor
Spin conditions: 35° fixed angle rotor, 7,500 × g, room temperature, 2 mL starting volume.
Protein markers used: Cytochrome c for 3K and 10K, BSA for 30K and 50K, and IgG for 100K, n=8.