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Message | User | Date(yyyy-mm-dd) |
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Storage conditions for PS Module | shunt | 2003-07-25 | Click here to register. |
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| I have not yet used my wet polysulfone module. I would like to know the proper storage conditions. | | |
| ppatel | 2003-07-25 | Click here to register. |
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 | Store the modules at room temperature until use. They should be good for 2 years after you order them. Make sure they are sealed properly so the storage media does not evaporate. |
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| shunt | 2003-07-25 | Click here to register. |
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| What about after i begin using them. How best to store them inbetween runs. |
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| ppatel | 2003-07-29 | Click here to register. |
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| These modules are disposable and not reusable so the storage between runs is usually not mentioned. Are you reusing them?
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| shunt | 2003-07-29 | Click here to register. |
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| I have not reused them yet, but i certainly believe that it should be possible to run different protein purification batches on different days (same protein, but different days). I realize the company line is to throw them out after a single use, but in reality there is a successful method of cleaning and storing. Do you have any recommended cleaning / storing conditions between batches of protein purification? |
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| ppatel | 2003-07-29 | Click here to register. |
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| This is a guide for general cleaning procedures for Spectrum hollow fiber tangential flow membranes. Even though you can anticipate repeated use of a membrane, you should expect that with each use the flux rate would diminish a little. The process time will increase slightly with each use. Since our membranes are so affordable compared to our competitors membranes, you will find that it is most cost effective to use a membrane about three to five times before replacing the membrane. Depending on specific process samples and parameters, it is possible to get even further use out of our hollow fiber membranes. In some cases it is best to use the membranes disposably.
This all needs to be determined for each sample and set of process conditions.
Cleaning: In general, cleaning should be performed at low pressures and high velocity, at temp. of 40- 50 degrees Celsius.
1) Before cleaning with any detergent, alcohol, acid or solution, it is extremely important to thoroughly flush the membrane with warm (50 degrees C) water or buffer first. The advantage to using a buffer flush is that water may cause proteins to precipitate and adhere to the surface of the membrane. Flush in a forward (Forward Flushing) direction and then also in a reverse direction (Reverse Flushing). If necessary, you may want to utilize a Back Flushing. While pumping the buffer or water in a forward direction, flow the same flush solution gently from permeate line back into the module housing. This will rinse the membranes from the outside (permeate side) in to the lumen of the fiber (retentate side) and down stream. While performing any of these flush procedures, it is best not to recirculate the flush solution or water. It is preferable to flush with a single pass through the membrane.
2) The following is the best procedure for cleaning microfiltration (MF) membranes used for clarification of whole cell lysate.
i) Flush with clean water, buffer or saline at 50 degrees C.
ii) Circulate with 0.5 N NaOH at 50 degrees C, pH 10-11, 1 hr.
iii) Flush with clean water.
The second best procedure for cleaning the MF membranes used for clarification follows:
i) Flush with clean water, buffer or saline at 50 degrees C.
ii) Circulate 0.2% Terg-A-Zyme at 50 degrees C, pH 9-10, 1 hr.
iii) Flush with clean water.
The third best procedure for cleaning the MF membranes used for clarification follows:
i) Flush with clean water, buffer or saline at 50 degrees C.
ii) Circulate 0.5% Henkel P3-11 at 50 degrees C, pH 7-8, 1 hr.
iii) Flush with clean water.
3) The following is the best procedure for cleaning ultrafiltration (UF) membranes used for protein purification and concentration:
i) Flush with clean water, buffer or saline at 50 degrees C.
ii) Circulate with 0.5 N NaOH at 50 degrees C, pH 10-11, 1 hr.
iii) Flush with clean water.
The second best procedure for cleaning the MF membranes used for clarification follows:
i) Flush with clean water, buffer or saline at 50 degrees C.
ii) Circulate 0.1% Tween 80 at 50 degrees C, pH 5-8, 1 hr.
iii) Flush with clean water.
The third best procedure for cleaning the MF membranes used for clarification follows:
i) Flush with clean water, buffer or saline at 50 degrees C.
ii) Circulate 0.2% Terg-A-Zyme at 50 degrees C, pH 7-8, 1 hr.
iii) Flush with clean water.
Those are the cleaning procedures for both the 0.5 um microfiltration (MF) membranes and 400 kD ultrafiltration (UF) membranes. Terg-A-Zyme can be purchased through Alconox, Inc. NY, NY (212) 532-4040. It is also most likely available through Fisher or VWR.
Sanitization: If you are interested in sanitizing the membranes, both the MF (PES only) and UF (PS) membranes can be sanitized by using any of the following methods.
1) Up to 100-ppm sodium hypochlorite circulated for 1 hr.
2) Up to 3% formalin circulated for 1 hr.
3) Up to 0.5 N sodium hydroxide circulated for 1 hr.
4) Up to 70% ethanol in water circulated for 1 hr.
Storage: Last but not least is storage. It is very important that you store the membranes properly so as to avoid growth of bacteria and fungus.
For short-term storage of a maximum of one week, they can be stored wet with water. If you want to store for longer periods, a preservative is required to prevent the growth of bacteria and fungus. The following is a list of recommended storage solutions.
1) 0.1% sodium azide.
2) 1% formaldehyde.
3) 1% sodium hydroxide.
4) 1% sodium benzoate.
When you want to re-use a membrane that has been stored for a long period, make sure to thoroughly flush out the storage solution with water, buffer or saline.
I hope this information proves helpful. If you follow these procedures for taking proper care of your membranes, you should be confident in the reuse of the membranes. Please remember that it is vital that once a membrane has been wetted, it must never dry out. If you try to re-wet and re-use a membrane that has dried out, the membrane will lose integrity and permit retentate to pass through into the permeate.
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| shunt | 2003-07-29 | Click here to register. |
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| I have not reused them yet, but i certainly believe that it should be possible to run different protein purification batches on different days (same protein, but different days). I realize the company line is to throw them out after a single use, but in reality there is a successful method of cleaning and storing. Do you have any recommended cleaning / storing conditions between batches of protein purification? |
| | |
| shunt | 2003-07-25 | Click here to register. |
|---|
| What about after i begin using them. How best to store them inbetween runs. |
| | |
| shunt | 2003-07-25 | Click here to register. |
|---|
| What about after i begin using them. How best to store them inbetween runs. |
|
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