PS-based Fluoroliposome® Containing Encapsulated Fluorescent Dextran
Description
Dextran is a branched polysaccharide containing glucose subunits. It is a large molecule that can not leak out of the liposomes over time while the liposomes are inside the vial. Dextran can be tagged with various fluorescent probes. Liposomes encapsulating fluorescent dextran can be used in experiments that require tracking of the fluorescent water-soluble cargo.
Dextrans conjugated to dyes such as pHrodo-Red and pHrodo-Green are pH sensitive and increase in fluorescence as pH decreases from more neutral to acidic. pHrodo-Red and pHrodo-Green conjugates are commonly used for detecting endocytosis and phagocytosis, respectively, as the dyes display little to no fluorescence outside the cell at neutral pH and upon internalization, emit a bright red or green signal due to the acidic environment of endosomes and phagosomes.
The liposome formulations encapsulating dextran fluorescent dyes are extensively dialyzed and cleaned up, so there is no need for the end-user to separate the encapsulated dextran fluorescent dyes from the non-encapsulated.
None of these liposomes can be used for fluorescent leakage assay. If the goal of your research is to monitor the leakage of a self-quench dye then we recommend using one of the products in Calcein/5,6-Carboxyfluorescein liposome-encapsulated catalog.
If you need to monitor both the fluorescent water-soluble cargo and the fluorescent lipid membrane, then we can add lipids containing pyrene to the lipid mix of the liposomes. Pyrene has an excitation/emission range of 351/379 nm which is far away from the excitation/emission range of all the fluorescent dextran dyes.
Technical Information
PS-based Fluoroliposome® Containing Encapsulated Fluorescent Dextran
Lipid Composition | Concentration (mg/ml) | Concentration (mM) | Molar Ratio Percentage |
---|---|---|---|
1,2-dioleoyl-sn-glycero-3-phospho-L-serine (sodium salt) | 1.62 | 2 | 20 |
1,2-dioleoyl-sn-glycero-3-phosphocholine | 3.93 | 5 | 50 |
Cholesterol | 1.16 | 3 | 30 |
Total | 6.71 mg/ml | 10 mM | 100 |
Fluorescent Dye | Excitation/Emission (nm) |
---|---|
Dextran-Fluorescein (MW=10K) | 494/521 |
Dextran-Texas Red™ (MW=10K) | 595/615 |
Dextran-Rhodamine B (MW=10K) | 570/590 |
Dextran-Tetramethylrhodamine (MW=10K) | 555/580 |
Dextran-pHrodo™ Red (MW=10K) | 560/585 |
Dextran-pHrodo™ Green (MW=10K) | 509/533 |
Buffer and Liposome Size | Specification |
---|---|
Buffer | 20 mM HEPES |
pH | 7.4 |
Liposome Size | 100 nm |
* If you prefer different buffers, please specify in your order. |
Technical Notes
- DOPS and DOPC are both unsaturated lipids and their liquid to gel phase transition temperature is below zero degree Celsius.
- DOPS and DOPC both have unsaturated fatty acid tails. The unsaturated lipid has “kinky legs” and therefore it makes loosely packed liposomes. Saturated lipids make tightly packed liposomes. The packaging of the liposomes will impact the interaction of the molecules with the surface of the liposomes.
- Liposomes are unilamellar and sized to 100 nm. If you need them to be made in another size, then you should mention that at the time of ordering. Unilamellar liposomes can be made in 50 nm and 200 nm sizes. Liposomes that are larger than 200 nm are multilamellar structure.
- Liposomes are made in HEPES buffer at pH 7.4 but it can be made in any other buffer of your choice. You can specify your buffer at the time of ordering.
- Liposomes are made in degassed buffer that is purged with argon to avoid oxidation of the unsaturated phospholipids.
- Liposomes are made under sterile condition.
- Liposomes are unilamellar and therefore due to their small size they will not settle in the bottom of the vial. a period of time, then it is advised to take extreme care in not contaminating the vial. It is recommended to handle the vial under a sterile hood to maintain the sterility of the product.
- Liposomes should never be frozen. Ice crystals that form during freezing will rupture the lipid membrane of the liposomes and change the size the liposomes particles.
- Liposomes should be kept in refrigerator at 4°C in order to avoid the hydrolysis of the liposomes.
- Liposomes should be kept at 4°C and NEVER be frozen.
Appearance
PS-based Fluoroliposome® containing encapsulated fluorescent dextran formulation is a colored translucent liquid, and the color depends on the type of the fluorescent dye that is used (see SDS for appearance). Usually due to the small size of liposomes no settling will occur in the bottom of the vial. The liposomes are packaged in an amber vial.
Ordering/Shipping Information
- All liposome based formulations are shipped on blue ice at 4°C in insulated packages using overnight shipping or international express shipping.
- Liposomes should NEVER be frozen. Ice crystals that form in the lipid membrane can rupture the membrane, change the size of the liposomes and cause the encapsulated drug to leak out. Liposomes in liquid form should always be kept in the refrigerator.
- Clients who order from outside of the United States of America are responsible for their government import taxes and customs paperwork. Encapsula NanoSciences is NOT responsible for importation fees to countries outside of the United States of America.
- We strongly encourage the clients in Japan, Korea, Taiwan and China to order via a distributor. Tough customs clearance regulations in these countries will cause delay in custom clearance of these perishable formulations if ordered directly through us. Distributors can easily clear the packages from customs. To see the list of the distributors click here.
- Clients ordering from universities and research institutes in Australia should keep in mind that the liposome formulations are made from synthetic material and the formulations do not require a “permit to import quarantine material”. Liposomes are NOT biological products.
- If you would like your institute’s FedEx or DHL account to be charged for shipping, then please provide the account number at the time of ordering.
- Encapsula NanoSciences has no control over delays due to inclement weather or customs clearance delays. You will receive a FedEx or DHL tracking number once your order is confirmed. Contact FedEx or DHL in advance and make sure that the paperwork for customs is done on time. All subsequent shipping inquiries should be directed to Federal Express or DHL.
Storage and Shelf Life
Storage
Liposomes containing encapsulated fluorescent dextran should always be stored at in the dark at 4°C, except when brought to room temperature for brief periods prior to animal dosing. DO NOT FREEZE. ENS is not responsible for results generated by frozen product.
Shelf Life
Liposomes containing encapsulated fluorescent dextran are made on daily basis. The batch that is shipped is manufactured on the same day. It is advised to use the products within 30 days of the manufacturing date.