A549 Cells for Tet-Inducible Gene Expression

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A549-RepTor™ Cells

TetR-expressing A549 cells

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3-7 x 10e6 cells

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Tetracycline repressor-expressing A549 cell line

Inducible gene expression in A549-RepTor™ cells
Inducible gene expression in A549-RepTor™ cells

A549-RepTor™ cells are derived from the human lung carcinoma A549 cell line, a widely used cellular model. These cells were specifically engineered for InvivoGen's TiGer tet-on system.

They are designed for the tetracycline-inducible expression of a gene of interest (GOI), including cytotoxic proteins. 



A549-RepTor™ cells stably and constitutively express an optimized tetracycline repressor (TetR) construct [1]. They are readily transfectable with a pTiGer plasmid, carrying a gene of interest (GOI), cloned downstream of the tet-inducible CMV-EF1-TRE promoter. GOI expression is induced upon addition of doxycycline, a synthetic analog of the tetracycline antibiotic, leading to the derepression of the CMV-EF1-TRE promoter. Low doxycycline concentration, ranging from 1 to 10 ng/ml, is sufficient for full induction, thus limiting the antibiotic side effects [2].


Key features

  • Strong and stable TetR expression for minimal GOI leakiness
  • Readily transfectable with a pTiGer-mcs or pTiGer-reporter plasmid
  • Strong GOI expression with a low doxycycline dose


pTiGer-transfected RepTor™ cells are useful for, but not restricted to the following applications:

  • Controlled expression of cytotoxic genes
  • Fine-tuned expression of a GOI
  • Screening of toxic protein inhibitors


RepTor™ cells are functionally validated by transient transfection with a pTiGer-reporter plasmid expressing either SEAP or Lucia luciferase. These cells are resistant to Blasticidin. ​They are also extensively tested for viability, stability, and absence of mycoplasma to ensure strong and reproducible results. 
For your convenience, RepTor™ cells are shipped with 1 mg of doxycycline and 10 mg of blasticidin.


Learn more about InvivoGen's pTiGer Tet-on system.



1. Hillen, W., Wissmann, A. (1989). Tet repressor-tet operator interaction. Protein-Nucleic Acid Interaction. DOI: 10.1007/978-1-349-09871-2_7.
2. Luger, AL., et al., (2018). Doxycycline Impairs Mitochondrial Function and Protects Human Glioma Cells from Hypoxia-Induced Cell Death: Implications of Using Tet-Inducible Systems. Int J Mol Sci, 19(5):1504.


No expression leakage of protein of interest
No expression leakage of protein of interest

Expression of SEAP or Lucia reporter proteins in transfected HEK-RepTor™ cells. HEK-RepTor™ cells were transfected with the gene coding for SEAP (secreted embryonic alkaline phosphatase) or Lucia luciferase cloned into a pTiGer plasmid. The cells were then treated, or not, with Doxycycline (Dox) at 1.25 or 2.5 ng/ml for 24 hours. (A, B) The SEAP activity in the supernatant of HEK-RepTor™ SEAP cells was assessed using QUANTI-Blue™ detection reagent. The data is shown as (A) OD at 650 nm and (B) fold increase (mean +SEM). (C, D) The Lucia activity in the supernatant of HEK-RepTor™ Lucia cells was assessed using QUANTI-Luc™ 4 Lucia/Gaussia detection reagent. The data is shown as (C) relative light units (RLUs) and (D) fold increase (mean +SEM).

Inducible SEAP or Lucia expression in A549-RepTor™ cells
Inducible SEAP or Lucia expression in A549-RepTor™ cells

Dose-dependent Doxycycline-mediated expression of SEAP or Lucia in A549-RepTor™ cells. A549-RepTor™ cells were transfected or not with the gene coding for SEAP (secreted embryonic alkaline phosphatase) or Lucia luciferase cloned into a pTiGer plasmid. A549-RepTor™ SEAP cells and A549-RepTor™ Lucia cells were incubated with increasing concentrations of Doxycycline. After 24 hours, the SEAP or Lucia activity in the supernatant was assessed using (A) QUANTI-Blue™ or (B) QUANTI-Luc™ 4 Lucia/Gaussia, respectively. The data is shown as fold induction over no Dox treatment (mean + SEM).

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Antibiotic resistance: Blasticidin

Growth medium: DMEM, 4.5 g/l glucose, 2 mM L-glutamine, 10% (v/v) fetal bovine serum, 100 U/ml penicillin, 100 μg/ml streptomycin, 100 μg/ml Normocin™

Quality Control:

  • Inducible reporter activity in the presence of doxycycline has been validated using A549-RepTor™ cells transfected with pTiGer2-SEAP.
  • The stability for 20 passages, following thawing, has been verified.
  • These cells are guaranteed mycoplasma-free.


These products are covered by a Limited Use License (See Terms and Conditions).

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  • 1 vial containing 3-7 x 106 cells
  • 1 ml Blasticidin (10 mg/ml)
  • 1 ml Normocin™ (50 mg/ml)
  • 1 mg Doxycycline


 Shipped on dry ice (Europe, USA, Canada, and some areas in Asia)

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Visit our FAQ Any questions about our cell lines ? Visit our frequently asked questions page

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Notification:  These products are for internal research use only. Additional rights may be available. Please visit InvivoGen’s Terms and Conditions.

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