Sinofection Transfection Reagent

Introduction to Sinofection

For DNA transfection of broad range of cell lines

Sinofection is a superior cationic polymer-based transfection reagent. It has been successfully applied to transfection at various scales over a broad range of cell lines. Compared with the leading transfection reagents on the market, Sinofection yields higher protein expression level and exhibits lower cytotoxicity. It is an ideal choice for recombinant protein production for both transient and stable transfection. Moreover, the stability study of Sinofection showed satisfactory stability at -20°C ~37°C for at least 6 months. Its extensive compatibility with serum, cell type, scale, and storage temperature offers you ease and assurance for research and production.

Features

• Superior protein expression
• Excellent transfection of both adherent and suspension cells for a broad range of cell lines
• Remarkable application of DNA transfection (transient/stable) at scales from microtiter plates to bioreactors
• Striking stability at 37°C
• Easy and fast procedure
• Low cytotoxicity

Quality Control

• Transfection efficiency:
  • Sinofection is lot tested against 293E cell line to assure consistency and efficacy. 85% confluent 293E cells in 24-well plate are transfected with 0.6 μg of an rhFc-expression plasmid using 2.8 μl of Sinofection.
• Sterility:
  • Sinofection is manufactured and packaged in sterile condition and filtrated through 0.22μm sterile filter for the last step.
• Cytotoxicity:
  • Cytotoxicity of Sinofection is evaluated by in-house WST-8 assay.

Superior protein expression

Transfection with Sinofection has been proved to provide higher levels of protein expression in several cell lines than leading competitor’s products. For large-scale production of recombinant proteins, Sinofection is the best choice to achieve the optimum yield. In addition, Sinofection also exhibits high transfection efficiency to ensure successful transfections.

Fig. 1 Protein expression levels by transient transfection using Sinofection and other competitors were compared in 9 cell lines, 6 of which showed superior results transfected by Sinofection (A~F). Protein expression level was determined by Elisa assay. The transfection by competitor transfection reagents followed the manufacturers’ protocols.

Excellent transfection of both adherent and suspension cells for a broad range of cell lines

Remarkable application of DNA transfection (transient/stable) at scales from microtiter plates to bioreactors

Hundreds of recombinant antibodies and proteins have been successfully expressed by transient or stable transfection with Sinofection at various scales, from 0.1ml in a 96-well plate to 50L in a bioreactor. Utilizing Sinofection for all scales of transfection application will save the cost of research and production to a great extent.

Striking stability at 37°C

Long-term stability test showed Sinofection remained its activity at 37°C for at least 4 months. Storage at -20°C~RT can maintain stable for at least 6 months. Exceptional stability resulted from rigorous screening and reliable investigation for a long time. Thus the stability of Sinofection can outperform any other transfection reagent.

Fig. 2. Stability test for Sinofection at 4 temperatures during 26 weeks. One recombinant antibody and recombinant VEGF-Fc were tested for expression level by transient transfection with Sinofection stored under different conditions. Expression level was assayed by Elisa.

Easy and fast procedure

Transfection protocol (35-mm dish):

Preparation of cells

• Adherent cells
  • One day before transfection, plate 0.2–2×10⁶ cells in medium per 35-mm dish. Incubate at 37°C (5% CO2) overnight. The confluency of cells should be 50–80% before transfection.
• Suspension cells
  • One day before transfection , Passaged cells at a density of 5 × 10⁴/ml to 1 × 10⁶/ml in a 35-mm dish. The cell number depends on your needs and the cell type to be transfected.The suspension cells should be in log growth phase at the time of transfection.

Preparation of Sinofection&DNA complexes

1. Dilute the required plasmid DNA amount with 0.5ml.appropriate diluent, such as 150mM NaCl, 300mM glucose, DMEM medium with or without serum, whichever is isotonic. mix sufficiently and Incubate for 5 min at room temperature.

2. Add the required Sinofection volume to the diluted DNA mix sufficiently and incubate the mixture for 3-20 minutes at room temperature to allow complexes to form. Do not incubate for longer than 20 minutes.

Transfection

Add the complexes drop-wise to cells and medium. Gently rock the dishes or wells to ensure even distribution.

Incubate cells at 37°C in a CO2 incubator for 18-48 hours (normally high expression is achieved after 72 hours) prior to protein expression assay.

Transfection protocol (flask):

Transfecting Cells for Protein ExpressionThis protocol is typically used to transfect DNA into 293 EBNA or CHO cells cultured in flasks. Use sterile DNA or filter-sterilize DNA before use (re-quantify your DNA after filtration).

All amounts are on a per flask basis for 30 ml cultures in a 125 ml shake flask; for other formats, see Table 2. Scaling up or Down Transfections.

Table 2. Scaling up or down transfections with Sinofection. Note: the actual conditions should be optimized by experiments.

1. Pass 293 cells at 0.3 × 105 cells/ml, shake at 175 rpm. After 72 hours, dilute cells to 1.0× 106 cells/ml, shake at 175 rpm. Transfect after 4 hours.
2. Pass CHO cells at 0.3 × 105 cells/ml, shake at 175 rpm. After 48 hours, dilute cells to 1.0× 106 cells/ml, shake at 175 rpm. Transfect after 4 hours.
3. Dilute the required plasmid DNA amount with appropriate diluent, such as PBS with Mg2+, 150mM NaCl, 300mM glucose, DMEM medium with or without serum, whichever is isotonic. Incubate for 5 min at room temperature. Add the required Sinofection volume to the diluted DNA and mix gently to assure a total volume of 1.5~3ml.
4. Incubate the mixture for 10-20 minutes at room temperature to allow complexes to form. Do not incubate for longer than 20 minutes.
5. Slowly add 1.5~3ml of DNA-lipid mixture into the 125ml flask containing cells while slowly swirling the flask.
6. Incubate transfected cell cultures at 37°C, 8% CO2 on an orbital shaker set to 175 rpm for both 293 cells and CHO cells.

Low cytotoxicity

Sinofection demonstrates very low cytotoxicity which is tested and verified by in-house WST-8 assay for each lot. The WST-8 assay is based on the colorimetric reduction of water soluble tetrazolium (WST) by mitochondrial dehydrogenase

The absorbance of formazan dye solution is in direct proportion to the number of viable cells. Compared with the prevalent WST-1 method, the sensitivity of WST-8 assay is higher meanwhile the solubility and stability of formazan dye is better.

Fig. 3. Microscopy comparison of HeLa cells and DG44 cells transfected with L2K and Sinofection respectively. Transfections were performed following the manufacturer’s recommendations.

Fig. 4. Cytotoxicity comparison of Sinofection and L2K for 4 cell lines. Transfections were performed following the manufacturer’s recommendations.