Amicon
®
Ultra-2 Centrifugal Filter Devices
3
10K
4
3
2
1
00
20
00
00
00
4
3
2
1
00
20
00
00
00
10K
Invert device and
concentrate tube
10K
4
3
2
1
00
20
00
00
00
Separate device
from filtrate tube
Filtrate
Concentrate
Spin to
recover
Desalting or Diafiltration
Desalting, buffer exchange, or diafiltration are important methods for removing salts or solvents in solutions containing
biomolecules. The removal of salts or the exchange of buffers can be accomplished in the Amicon
®
Ultra-2 device by concentrating
the sample, discarding the filtrate, then reconstituting the concentrate to the original sample volume with any desired solvent. The
process of “washing out” can be repeated until the concentration of the contaminating microsolute has been sufficiently reduced.
See example below.
Spin to
concentrate
2 mL of
1 mg/mL
protein in
100 mM NaCl
50 µL of
40 mg/mL
protein in
100 mM NaCl
100 mM NaCl
50 µL of
40 mg/mL
protein in
12.3 mM
NaCl
12.3 mM NaCl
Add 1.95 mL of
10 mM NaCl or
exchange buffe
r
2 mL of
1 mg/mL
protein in
12.3 mM
NaCl
10K
4
3
2
1
00
20
00
00
00
10K
4
3
2
1
00
20
00
00
00
10K
4
3
2
1
00
20
00
00
00
10K
4
3
2
1
00
20
00
00
00
Spin to
concentrate
Performance - DNA Concentration
The Amicon
®
Ultra-2 30K device provides the best balance between PCR recovery and PCR primer removal for double-stranded
DNA for base pairs ranging from 137 to 1159.
Table 1. Typical Recovery of Nucleotides from the Amicon
®
Ultra-2 30K Device
Swinging Bucket Rotor
35° Fixed Angle Rotor
4,000 × g for 40 min
7,500 × g, for 15 min
PCR
Product
(base
pairs)
PCR
Primer
(bases)
PCR
Recovery
(%)
PCR
Primer
Removal
(%)
Final
Voume
(µL)
PCR
Recovery
(%)
PCR
Primer
Removal
(%)
Final
Volume
(µL)
137
10
20
48
83
87
86
92
80
61
44
43
41
78
75
78
93
86
67
27
22
25
1159
10
20
48
96
97
97
98
93
82
35
39
37
95
93
95
98
93
82
26
26
27
100 µL PCR diluted to 2,000 µL starting volume, n=6