Protein Sample Preparation: Dialysis - D-Tubes

D-Tube^™ Dialyzers

D-Tube™ Dialyzers are easy-to-handle dialyzers in a capped centrifuge tube format with dialysis membrane windows for buffer exchange and removal of solutes like urea or detergents while providing > 97% sample volume recovery from solution.

The disposable, single-use tubes require no syringes, centrifuge, or laborious steps to manipulate small sample volumes. The sample is added and removed using a standard laboratory pipette. D-Tube™ Dialyzers are available with molecular weight cut-offs from 3.5 to 14 kDa and are designed with six volume capacities:

mini (10–250 μL)
midi (50–800 μL)
maxi (100– 3000 μL)
and mega (10, 15, and 20 μL)

The membrane is ultra-clean, EDTA-treated regenerated cellulose, sulfur- and heavy metal-free. Each kit contains 10 D-Tube™ Dialyzers (Mega kits available in 10 and 50 pk) and one floating rack that can hold up devices in an exchange buffer.

Order D-Tube™ Dialyzers

Sample Type	Method	Typical Recovery
Sample in Solution	Dialysis	> 97%
DNA or RNA in aga rose gel slice	Electroelution	> 90%
Oligonucleotides, DNA, or RNA in polyacrylamide gel slide	Electroelution	> 90%
Protein polyacrylamide gel slide	Electroelution	60%

Advantages:

89% Sample Recovery
- Low binding membrane and housing enhance sample recovery
Reliable and Easy to Use
- Secure design prevents sample loss due to leaks — no knots or clamps to loosen and leak
- Easy to open and close with a screw cap
- Rigid frame permits smooth sample withdrawal of submilliliter volumes — removing every last drop is easy
Convenient Sample Loading
- No need to use a syringe to load or remove samples. Simply load your sample with standard pipette tip
- Floating racks fit most standard beakers to hold devices in exchange buffer
- D-Tube™ dialyzers can also be used to electroelute samples from agarose or acrylamide

D-Tube™ Dialyzers provide gentle, efficient desalting and excellent protein recovery. A bovine serum albumin (BSA) solution in 2M NaCl was dialyzed against water while water conductivity was monitored. After 100 minutes, conductivity of the water stopped increasing, and it was replaced with fresh water. After 5 hours, 89% of the protein was recovered, and 99.9% of the salt had been removed.