PROTOCOL

Dharmacon™ DharmaFECT™
kb transfection reagent
The following is a general protocol for use of DharmaFECT kb transfection
reagent to deliver plasmid into cultured mammalian cells. The examples
given within the protocol are for 96-well plates, and Table 1 provides thetransfection reagent volumes for additional plate types.

Reagents to be supplied by the user
Cells and appropriate growth medium. Appropriate antibiotic if researcher
will perform selection.

General considerations
DNA quality requirements
DNA quality is critical for successful transfection. An A260/A280 ratio of 1.8
is recommended. Endotoxin-contaminated DNA may result in inefficienttransfection and cause unacceptably high cellular toxicity.
Cell density
The recommended confluency for adherent cells on the day of transfection is70–90%. Suspension cells should be in logarithmic growth phase.

Incubation time
Transient transgene expression takes place within 24-72 hours after
transfection. The optimal incubation time depends on the cell type,promoter strength and expression product, and must be determined
experimentally.
Transfection reagent and DNA amounts
The volume of transfection reagent used depends on the amount of DNA,transgene, and cells to be transfected. The ranges presented in the protocols
below are starting amounts and should be further optimized for best results.
Choice of promoter
High transgene expression depends both on the transgene promoter andon the cell line used. Cytomegalovirus (CMV) promoter is commonly used
for high gene expression in a variety of cell lines. Other promoters such aselongation factor 1 alpha (EF1a), ubiquitin C (UBC), phosphoglycerate kinase(PGK) and chicken beta actin hybrid (CAG) can also be used.

General protocol for transfection of adherent cells in 96-well format
Quantities and volumes should be scaled according to the number of wells to be transfected (Table 1).
1. In each well, seed cells in 100 μL of growth medium 24 hours prior to transfection at a density that will give a confluency of 70-90% for adherent cells on
the day of transfection. Suspension cells should be in logarithmic growth phase at the time of transfection.
2. Dilute DNA in 10 μL per well of serum-free DMEM or other serum-free growth medium.
We recommend starting with 100-200 ng DNA per well. The amount of DNA used per well depends on transgene expression, assay to beused, and cell line. Amount of DNA should be optimized for each experiment.
3. Gently mix DharmaFECT kb transfection reagent by pipetting.
4. Dilute DharmaFECT kb reagent in 10 μL per well of serum-free DMEM or other serum-free growth medium.
Prepare immediately prior to transfection. User should optimize volume of DharmaFECT kb reagent used based on experimental system.
Optimization of DharmaFECT kb reagent and DNA amounts will increase transfection efficiency specific for the cell line and transgene used.
5. Add 10 µL diluted DharmaFECT kb reagent to the diluted DNA for a total of 20 µL per well.
6. Incubate 10 minutes at room temperature.
7. Add 80 µL of growth medium to the complex and mix.
The transfection efficiency with DharmaFECT kb™ transfection reagent (Cat #T-2006-01) is equally high in the presence of serum. This is not
the case with other transfection reagents.

8. Gently aspirate medium from cell culture plate.
9. Immediately dispense 100 μL of the transfection reagent/DNA mixture to each well.
10. Gently rock the plate to achieve even distribution of the complexes.
11. Incubate at 37 °C in a CO2 incubator.
12. Begin to analyze transgene expression 24-72 hours later. For stable transfection, cells should be grown in selective medium.
If using DNA containing a fluorescent reporter gene, and you observe less than 90% of all cells expressing the transfected reporter gene,first try optimizing transfection conditions by varying cell confluency or density, volume of DharmaFECT kb reagent, and amount of DNA.
If after optimization of transfection conditions less than 90% of cells express the reporter, antibiotic selection is recommended toeliminate those cells from the population that are not transfected.
Table 1. Scale-up ratios for transfection of adherent and suspension cells with DharmaFECT kb transfection reagent.

Amount of DNA

Volume of DharmaFECT kb, μL

µg**

µL***

Recommended

Range

0.1

4

0.5-1.2 × 10 (2.0 × 10 )

0.2

10

0.6

0.4-1.0

0.7

0.25

4

1.0-3.0 × 10 (5.0 × 10 )

0.525

1.5

0.8-2.2

2.0

0.5

2.0-6.0 × 104 (1.0 × 105)

1.050

3.0

2.0-5.0

4.0

1.0

0.4-1.2 × 105 (2.0 × 105)

2.0

100

6.0

3.9-9.0

6-well plate

9.5

2.00.8-2.4 × 105 (4.0 × 105)

4.0

200

9.0

6.0-12.0

60 mm plate

20

3.0

2.0-6.3 × 105 (1.0 × 106)

6.0

300

18.0

12.0-24.0

Tissue culture vessel

Growth area,
cm2/wellVolume ofmedium, mL

Adherent (suspension) cells to seed
the day before transfection*

96-well plate

0.3

48-well plate24-well plate
12-well plate

44* These numbers were determined using HEK293T and U2OS cells. Actual values depend on the cell type.
** Amount of DNA and DharmaFECT kb transfection reagent used may require optimization.
*** The volume of DNA should be 1/10 of the volume of the culture medium used for dilution of the DNA.

Antibiotic selection
If the transfected vector confers resistance to Blasticidin S (Fisher Scientific,Cat #BP2647-25), puromycin (Fisher Scientific, Cat #BP2956-100), or anotherantibiotic, selection can be used to eliminate non-transfected cells. In order togenerate stable cell lines, it is important to determine the minimum amountof antibiotic required to kill non-transfected cells. This can be done byconducting a dose response curve on the cell line of interest.

Protocol for selection using Blasticidin Sor puromycin
If adding antibiotic for selection, use the appropriate concentration as
determined based on the above dose response curve.
1. Add medium containing antibiotic 24 hours post-transfection
to begin selection.

2. Cells can be harvested for transgene expression 24-72 hours after
starting selection.
It is important to wait at least 24 hours after transfection
before beginning selection.
3. If longer selection is required for cells to be confluent, replace selective
medium approximately every 2-3 days.
4. Monitor the cells daily and observe the percentage of surviving cells.
Cells surviving selection will be expressing the transgene.
5. If generating stable cell lines (optional), select and grow for 10-15 days.
6. Once non-transfected cells are eliminated and/or you have selected
for stably transfected cell lines if desired, you can proceed to assay fortransgene expression. RT-qPCR, western blot analysis or other appropriate
functional assay can be used; compare treated samples to untreated,
reporter alone, non-silencing control, or other controls as appropriate.

Frequently asked questions (FAQs)

Question

Answer
If reagent seems to be toxic to a particular cell line, try reducing.

How can the DNA and DharmaFECT kb reagent
be adjusted to improve transfection efficiency?

Approximately how many transfections areavailable in each vial of DharmaFECT kb reagent?

If low transfection efficiency is due to a suboptimal, try using different amounts of the transfection reagent while
keeping the amount of DNA constant.
If low transfection efficiency is due to a suboptimal amount of DNA, keep the constant while adjusting theamount of DNA used in the transfection.
The number of transfections that can be performed with each vial of DharmaFECT kb reagent will vary dependingon the tissue culture plate used and the cell type. For example, the 1 mL vial of DharmaFECT kb will be sufficientfor ~ 330 transfections in the 24-well plate format.

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TurboGFP is a trademark of Evrogen JSC. All trademarks are the property of Horizon Discovery Company unless otherwise specified. ©2018 Horizon
Discovery Group Company—All rights reserved. First published June 2014. UK Registered Head Office: Building 8100, Cambridge Research Park,Cambridge, CB25 9TL, United Kingdom.

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