A. Problem
While working with proteins and nucleic acids, it is very often necessary to eliminate small molecular weight substances such as reducing agents [dithiothreitol (DTT), 2-mercaptoethanol (BME), urea], un-reacted crosslinking or labeling reagents (sulfo-SMCC, biotin) and preservatives (sodium azide, thimerosal) that might interfere in subsequent steps of the experimental protocol. Methods such as dialysis and electro-elution (for extraction of nucleic acids from gels) have long been used to purify proteins and nucleic acids. However, these traditional methods are riddled with numerous problems which may lead to tremendous time consumption, sample loss, contamination and high sample dilutions requiring further concentration.
B. Solution
DiaEasy™ Dialyzer tubes product line offers a solution to most of these issues. Our Dialysis tubes come in easy to use sets of 10, 25 and 100 tubes each, catering to different molecular weight cut-offs of 1 kDa, 3.5 kDa, 6-8 kDa, 12-14 kDa, 25 kDa and 50 kDa for different sample volumes ranging from 10 µl to 20 ml. These sets also contain floating racks and/or supporting trays for convenient handling of the tubes in the exchange buffer and electroelution. The combination of DiaEasy™ Dialyzer tubes and the electroelution accessories provides a unique tool for extraction of any protein, protein-protein, or protein DNA complexes from non-denaturing and denaturing (SDS) polyacrylamide gels, and for extraction of oligonucleotides, RNA, and DNA from both polyacrylamide and agarose gels. The DiaEasy™ tube’s membranes are ultra-clean, sulfur and heavy metal free and EDTA treated which makes the harvested proteins and nucleic acids suitable for molecular biology experiments. These DiaEasy™ tubes allow rapid, secure and simple loading and recovery. They are very high performance dialysis tubes and are the most convenient, user friendly dialysis system on the market. We offer these tubes with related accessories like supporting trays and floating racks for easy use.
C. Applications of DiaEasy™ Dialyzer tubes
- • Dialysis or buffer exchange of six different samples volumes: 10-250 µl, 50-800 µl, 0.1-3 ml, 10 ml, 15 ml and 20 ml.
- • High throughput dialysis (using a single beaker with several DiaEasy™ tubes on one floating pad).
- • Preparation of protein samples for MALDI-MS.
- • Samples concentration.
- • Large-scale protein dialysis such as antibodies and recombinant protein purification.
- • Peptide dialysis as small as 10 amino acids.
- • Virus-particle purification.
- • Removal of contaminating micro molecules.
- • Tissue culture extracts purification.
- • Removal of salts, surfactants, solvents & detergents.
- • Complex formation studies (protein-protein, protein-DNA and protein-RNA).
- • pH and buffer adjustment of sample solution, protein extract or cell extract.
- • 2D gel dots extraction.
- • Extraction of proteins, RNA, DNA or oligonucleotides (>20 nt) from polyacrylamide, agarose or any gel matrix in any running buffer.
D. Advantages of DiaEasy™ Dialyzer tubes
- • Most convenient, efficient and user-friendly dialysis sets on the market.
- • Single step efficient dialysis saves time and eliminates the need for additional equipment.
- • Samples pass through the tubes once, eliminating repeated dilutions and concentrations.
- • Single step decreases the risk of potential protein aggregation and precipitation and ensures high activity retention.
- • Elution times are as low as 10 minutes and range upto 150 minutes based on multiple criteria including the sample content, size and volume.
- • These sets are HTP compatible.
E. Typical Recovery Rates
Dialysis of samples |
≥ 98% |
Electroelution of DNA or RNA from Agarose gel |
≥ 90% |
Electroelution of DNA or RNA from polyacrylamide gel |
≥ 90% |
Electroelution of Protein from SDS-PAGE gel |
≥ 70% |
F. Advantages of DiaEasy™ Dialyzer tubes over conventional dialysis methods:
Conventional Dialysis |
DiaEasy™ Dialyzer Tubes |
Advantages |
Multistep protocol |
Single step |
Time efficiency |
High potential for protein aggregation and precipitation |
Minimal potential for protein aggregation and precipitation |
Eliminates need for post dialysis sample treatment before use in downstream applications |
Potential for loss in protein activity |
Retains maximum protein activity due to minimal processing time |
Ensures highly usable protein for any downstream applications |
Non-high throughput compatible |
High throughput compatible |
Can be used for large-scale protein dialysis such as antibodies and recombinant protein purification. |
Low sample recovery/yield |
≥ 98% protein recovery/yield |
High yield |
High contamination |
Low potential for contamination |
Purer sample recovery |
Requires additional equipment |
No requirement for any other equipment |
Simple to use |
Requires membrane preparation |
Ready to use |
No preparation required |
Can lead in sample leakage |
No sample leakage |
Maximum recovery |