11668-027 - FAQs

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13 个常见问题解答

How does the use of Lipofectamine 2000 reagent improve transfection over the other lipid reagents?

It generally yields better transfection activity (as measured by protein expression) than all other lipids in a majority of the cell lines tested. It includes a streamlined, simple protocol where the complexes are added directly to cells without changing media. This lends itself to high throughput applications. It works very well in the presence or absence of serum. Examples of cells that show the highest transfection efficiency with Lipofectamine 2000 include 293 F, 293 H, BE(2)C, CHO-K1, CHO-S, COS-1, COS7-L, Human Primary Fibroblasts, Ht-29, HT-1080, MDCK, MRC-5, PC12 and Vero.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

I've mistakenly frozen my cationic lipid reagent, can I still use it?

It is safest not to use it, however if the lipid is thawed very slowly at 4°C and its appearance did not change, it is probably worth trying. Lipofectamine 2000 has survived one freeze/thaw without loss of activity.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

How do I scale up or down my transfection reaction?

The number of cells, DNA, lipid, and medium volumes should be scaled up proportionately to the surface area of the plate. For commonly used culture vessels, please refer to the information below regarding actual area and area relative to a 24-well plate well.

Vessel type, Area (cm2), Area Relative to 24-well
96-well, 0.3 cm2, 0.2
48-well, 0.7cm2, 0.4
24-well, 2 cm2, 1
12-well, 4 cm2, 2
6-well, 10 cm2, 5
35 mm, 10 cm2, 5
60 mm, 20 cm2, 10
100 mm, 60 cm2, 30
150 mm, 140 cm2, 70
T25, 25 cm2, 12.5
T75, 75 cm2, 37.5
T150, 150 cm2, 75
T162, 162 cm2, 81
T165, 165 cm2, 82.5
40-50 ml, 25 cm2, 12.5
250-300 ml, 75 cm2, 37.5
650-750 ml, 162-175 cm2, 81-87.5
900 ml, 225 cm2, 112.5


Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

How do cationic lipids compare with calcium phosphate in transfection efficiency?

For many cell types, higher efficiencies are observed with cationic lipids than with calcium phosphate. Also, cationic lipid data are more reproducible from experiment to experiment. Calcium phosphate is inexpensive however, but pH variation as little as 0.2 can reduce transfection efficiency significantly.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

Can lipid reagents be used to cotransfect plasmids?

Yes. The standard transfection protocol may be followed by keeping the total amount of DNA in the mixture constant. That is, if your protocol requires 1 ug plasmid, use 0.5 ug of each of two cotransfecting plasmids, or 0.25 ug of each of 4, etc. When performing cotransfections to introduce a selectable marker on a different plasmid, we recommend using a 3:1 to 10:1 molar excess of the plasmid of interest over the selectable plasmid to ensure that the plasmid of interest is present with the selectable plasmid.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

What is the shelf life of the lipid transfection reagents?

Stored at 4°C in a sealed container, the lipids are stable for 12 months. Do not freeze the lipids. At 4°C with long term storage, due to evaporation concentration of lipid may vary, please briefly spin the contents before use. Add less lipid if you start noticing toxicity.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

What types of molecules can be transfected with cationic lipid reagents?

Lipid reagents can be used to transfect DNA, RNA, oligonucleotides and siRNA. The DNA can be plasmids, cosmids, or even YAC clones up to 600 kb. Lipofectin and Lipofectamine 2000 Reagent have also been used to transfect cells with proteins (Beta galactosidase and T3 polymerase).

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

Does the method of generating lipid-DNA complex affect transfection efficiency?

YES. Please follow the recommended procedure for each one of the reagents, found in the product manual.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

Can I use the same amount of any lipid reagent for transfection of my particular cell line?

No. The amount of lipid for each lipid reagent should be optimized for each cell line. Each lipid reagent has different composition/formulation, which will have different impact on each cell line. Therefore please optimize whenever you have a new lipid for each cell line.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

I have optimized my conditions for a particular cell line but I seem to be getting inconsistent results with my transfection. What factors contribute to this inconsistency?

Cells from a different passage number may behave differently. Also, if cells were sitting at confluence prior to plating for transfection, they may not transfect efficiently. To minimize such inconsistencies, passage the cells while they are still growing exponentially. Actively dividing cells transfect better.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

What kind of tubes can I use to form DNA:lipid complexes?

Polypropylene, polystyrene, or glass tubes may be used with any of our transfection products.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

Are there any guidelines for choosing a lipid transfection reagent?

It is best to optimize for your cells and application. Here are some basic guidelines:

- Lipofectamine LTX and PLUS Reagent: Minimal optimization, excellent efficiency with adherent eukaryotic cells DNA, difficult cell lines
- Lipofectamine Reagent: Adherent eukaryotic cells, DNA, oligonucleotides
- Lipofectin Reagent: Transfecting DNA in eukaryotic cell
- Cellfectin II: Insect cells
- DMRIE-C Reagent: DNA, RNA, suspension cells
- Oligofectamine: Oligonucleotides
- Lipofectamine RNAiMAX: siRNA, pre-miR, miRNA, anti-miR

NOTE: Please also visit our online Transfection Selection Tool to get specific recommendation for your cell line


Find additional tips, troubleshooting help, and resources within our Transfection Support Center.

In the case of the 96-well protocol, Lipofectamine 2000 requires 320 ng DNA, whereas Lipofectamine PLUS, or Lipofectamine LTX requires up to 200 ng DNA. Does this mean that more DNA is needed to transfect efficiently when using Lipofectamine 2000?

Yes, you do need more DNA per well when using Lipofectamine 2000, because the optimal confluency of the cells is 90% (as compared to 50-80% confluent with Lipofectamine, or Lipofectamine LTX. Therefore you need more DNA in order to ensure that the maximum number of cells are transfected. With Lipofectamine 2000, we have found empirically that the higher confluence (~90%) of cells at the start of transfection improves transfection efficiency.

Find additional tips, troubleshooting help, and resources within our Transfection Support Center.