Does the Slide-A-Lyzer Dialysis Cassette leak?
The innovative, patented design does not permit “wicking” that can occur with homemade microdialysis devices.
What sizes are available for the Slide-A-Lyzer Dialysis Cassette? What MWCO membranes are available?
Four sizes to accommodate samples between 0.1 and 30 ml are currently available in five different MWCOs (2K, 3.5K, 7K, 10K and 20K).
The G2 Slide A lyzers on the other hand are available in five different sizes to accommodate samples between 0.25 and 70mL.
These units, especially those that accommodate smaller volumes, provide for greater sample recovery and shorter dialysis times than one can achieve with traditional tubing. We have a cassette selection guide to help you choose the appropriate cassette for your application. There are also product demonstrations for this and other High-Performance Dialysis Products.
What prevents the Slide-A-Lyzer Dialysis Cassette from leaking?
An internal gasket, which isn't visible after the cassette is assembled, reseals itself as the needle is withdrawn. To maintain sample volume and integrity, users should remember these three key rules:
1. Before use, fill the cassette with air to verify that the system is airtight.
2. Puncture each porthole only once.
3. Do not allow the membrane to come into contact with the sharp needle bevel.
What is the purpose of the buoy for the Slide-A-Lyzer Dialysis Cassette?
The buoy suspends the Slide-A-Lyzer Cassette above the stirring bar during dialysis and it provides a benchtop stand on which to set the Slide-A-Lyzer Cassette. These are not required with the G2 Slide-A-Lyzer Dialysis Cassettes.
What is the highest temperature and the pH range that is compatible with the Slide-A-Lyzer Cassette?
Slide-A-Lyzer Cassettes can be held at 56 degrees C for two hours. At temperatures and times above these, the plastic gets soft and can deform. Thermo Scientific recommends that users maintain a pH range of 5-9.
Is the Slide-A-Lyzer Dialysis Cassette compatible with organic solvents?
Thermo Scientific researchers have successfully used 10% solutions of DMF, DMSO, acetonitrile, methanol, hexane and heptane; 100% acetic acid; and 70% ethanol with the Slide-A-Lyzer Cassette. The units are compatible with sample containing up to 75% acetonitrile and 1% TFA; however, Thermo Scientific recommends not dialyzing into a buffer that contains an acetonitrile concentration greater than 10%.
The casing is made of ABS plastic and the gasket is made from a non-leaching silicone-like material. The membrane is made from regenerated cellulose.
Is it necessary to extensively wash or boil the Slide-A-Lyzer Cassette before use to remove contaminants?
No. The Slide-A-Lyzer Cassette membrane requires no pretreatment. Trace metals are present in all Slide-A-Lyzer Cassette membranes. The 7,000 MWCO membranes contain 13% glycerol, 10,000 MWCO membranes contain 12% glycerol and 10,000 MWCO membranes contain 21% glycerol. These items will be lost during the dialysis process. To remove these items before introducing the sample, dialyze against water or a buffer for 10-15 minutes.
Is it necessary to buy needles and syringes from Thermo Scientific if there are already some available in the lab when using the Slide-A-Lyzer Dialysis Cassette?
No, any 18-gauge needle that is at least one-inch long and any syringe that is of sufficient volume will work.
If the Slide-A-Lyzer Dialysis Cassette is not reusable, why are there four portholes?
It is possible to add reagents to the Slide-A-Lyzer Dialysis Cassette at different times using different portholes, allow a reaction to occur, and then dialyze in the same Slide-A-Lyzer Dialysis Cassette, reducing sample loss through reduced sample handling.
How much sample will I lose in the Slide-A-Lyzer Cassette?
The Slide-A-Lyzer Cassette membrane is made of the same regenerated cellulose that is used in dialysis tubing, so a researcher should expect about the same protein loss one would experience with tubing. As a guide, a 1 mg/mL solution will generally have a recovery rate of greater than 95%. At 100µg/mL, the recovery rate drops to 75%-80%. With a dilute (e.g., 10 µg/mL) protein solution, one can lose up to 50% or more of the sample.
How long should I dialyze with the Slide-A-Lyzer Cassette?
Typically, one should dialyze for one hour at room temperature three times in dialysate that is about 300 times the sample volume. If required, dialysis may continue overnight at 4 degrees C to yield a more complete dialysis. Because each sample is different, the optimum time must be derived empirically.
How much sample will I lose in the Slide-A-Lyzer Dialysis Cassette?
The Slide-A-Lyzer Dialysis Cassette is the same regenerated cellulose as other dialysis tubing so you can expect about the same amount of protein loss as with tubing. As a guide, a 1 mg/mL solution will have a recovery rate of greater than 95%; at 100 mg/mL the recovery drops to 75-80%; and in solutions as dilute 10 µg/mL users may observe only a 50% (or less) recovery.
What conditions do you recommend for dialysis?
Dialyze for the amount of time sufficient to remove low molecular weight compounds for the specific downstream application. A typical dialysis procedure is as follows:
1) Dialyze for 2 hrs at room temperature or 4 degrees C.
2) Change the dialysis buffer and dialyze for another 2 hrs.
3) Change the dialysis buffer and dialyze overnight at 4 degrees C.
Use the dialysis buffer at 200-500 times the volume of the sample. For example, if the starting sample volume is 1 mL, then use a dialysis buffer amount that is equal to 200 mL-500 mL for each dialysis buffer change.
What is the buoy for?
The buoy plays two roles: it suspends the Slide-A-Lyzer Dialysis Cassette above the stirring bar during dialysis; it provides a stand to set the Slide-A-Lyzer Dialysis Cassette in on the bench-top
Is it necessary for me to buy needles and syringes if I already have them?
No, any 18 gauge needle at least one inch long, and syringes of sufficient volume will work.
What is the highest temperature and the pH range that is compatible with the Slide-A-Lyzer Dialysis Cassette?
The Slide-A-Lyzer Dialysis Cassette can be held at 56 degrees C for 2 hours. At temperatures and times above these, the ABS plastic gets soft and can deform. We recommend maintaining the pH range of 5-9.
Do I have to extensively wash or boil the Slide-A-Lyzer Dialysis Cassette before use to remove contaminants?
No. The Slide-A-Lyzer Dialysis Cassette membrane is of a grade used for human kidney dialysis and requires no pretreatment. However, when using small volumes we do recommend pre-wetting the units in deionized water for 30 seconds. Trace metals and 12% glycerol are present in all Slide-A-Lyzer Dialysis Cassettes. During the dialysis process these will dialyze away to virtually no concentration remaining in the cassette.
What materials are used to make Slide-A-Lyzer Dialysis Cassettes and are they compatible with organic solvents?
The plastic casing is made of ABS plastic and the gasket is made from a non-leaching silicone-type material. The membrane is made from regenerated cellulose. We have successfully used 10% solutions of DMF, DMSO, acetonitrile, methanol, hexane, heptane, 100% acetic acid, and 70% ethanol with the device. The units are compatible with 75% acetonitrile and 1% TFA in the sample, however we recommend not dialyzing into a buffer of acetonitrile concentration greater than 10%.
What sizes of the Slide-A-Lyzer Dialysis Cassette are available and in what MWCO?
There are 3.5 K, 7K, 10K, and 20K MWCOs available in 0.1-0.5 mL, 0.5-3 mL, 3-12 mL, and 12-30 mL. These units, especially at the smaller volumes, provide for greater sample recovery and shorter dialysis times than traditional tubing due to their greater surface area-to-volume ratio. For samples smaller than 100 µL, use the Slide-A-Lyzer MINI Dialysis Units and for larger volumes, refer to our SnakeSkin Dialysis Tubing.
Can I reuse the Slide-A-Lyzer Dialysis Cassette?
No, the Slide-A-Lyzer Dialysis Cassette is designed as a single-use, disposable device. Once hydrated, the membrane immediately begins to dry after the sample is removed: and the whole membrane will be dry within a few minutes, changing the molecular weight cut-off (MWCO).
Why doesn‘t the Slide-A-Lyzer Dialysis Cassette leak?
There is an unseen internal gasket which reseals as the needle is withdrawn. The most important items to remember are:
Fill with air first to check that system is airtight
Puncture each porthole only once
Do not allow the membrane to come in contact with the sharp bevel of the needle
What are the advantages of using a cassette for dialysis over traditional tubing methods?
Cassettes have easy handling and secure sample delivery, while traditional tubing is slippery when wet and can be difficult to handle, increasing risk of sample loss during sample addition/removal. Cassettes provide sample protection with a welded membrane and leak-proof cap, helping to minimize the risk of sample loss, whereas with traditional tubing, samples can leak out if the clamp is loose/falls off. Lastly, cassettes are fast and efficient with high surface/volume ratio allowing for more rapid dialysis than conventional tubing.
How is dialysis performed using the Slide-A-Lyzer Cassette (first generation)?
Please see the protocol summary below:
Insert syringe needle through the gasket via one of the corner ports. Inject the sample, withdraw the excess air and remove the syringe.
Attach a float buoy and dialyze. (Buoys also serve as convenient bench-top stands for the cassettes).
Insert empty syringe needle at a second corner port. Inject air to expand the cassette chamber, then withdraw the dialyzed sample.
What is the difference between a pack and a kit for the Slide-A-Lyzer cassettes?
The kit includes float buoys and syringes, and are only available for first-generation products. Please note that floats and syringes can also be purchased separately.
Are these Slide-A-Lyzer cassettes sterile?
We do not test for or claim sterility.
Do you offer gamma-irradiated array Slide-A-Lyzer cassettes?
Yes, we offer gamma-irradiated array Slide-A-Lyzer cassettes for both first-generation products (Cat. No. 66454, 66455, 66453, 66456) and second-generation products (Cat. No. 88250, 882551, 882552, 882553, 882554).
What is the difference between the original and second-generation Slide-A-Lyzer Cassettes?
The first generation cassettes can require a syringe to insert the sample, and may require a float buoy. They can hold 0.5-30 mL solution. The second-generation cassettes can be loaded with a syringe or pipet, are self-floating, and can hold 0.5-70 mL.
What is the difference between your dialysis devices (plates, device, cassettes, flasks)?
Please view our selection table to choose the right dialysis device for your experiment - https://www.thermofisher.com/us/en/home/life-science/protein-biology/protein-purification-isolation/protein-dialysis-desalting-concentration/dialysis-products.html.
What is protein dialysis?
Dialysis is the separation of small and large molecules in a solution by selective diffusion through a semi-permeable membrane. It is generally used for larger sample volumes, and can take hours to overnight for complete dialysis.
