4T1-Fluc-Neo/iRFP-Puro is a polyclonal population of the mouse mammary carcinoma cell line 4T1 (ATCC® CRL-2539™). To achieve stable reporter expression in the polyclonal population, parental 4T1 cells were transduced with LV-Fluc-P2A-Neo (LV011) and LV-iRFP-P2A-Puro (LV032) and selected using G418 and puromycin. LV-Fluc-P2A-Neo encodes the firefly luciferase (Fluc) cDNA linked to the neomycin resistance gene (Neo) via a P2A cleavage peptide under the spleen focus-forming virus (SFFV) promoter. LV-iRFP-P2A-Puro encodes the near-infrared fluorescent protein (iRFP) cDNA linked to the puromycin resistance gene (Puro) via P2A under the SFFV promoter.

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This cell line has been tested for mycoplasma contamination and is certified mycoplasma free.

The parental 4T1 cell line has been authenticated and certified free of interspecies cross contamination by short tandem repeat (STR) profiling with 9 STR loci.

Due to the immunogenicity of the reporter genes in this cell line, we recommend using immunocompromised mice for in vivo studies.

Replication Competent Lentivirus (RCL) Test (including a test report) is available for this cell line at an added cost.  Contact us to learn more.

Morphology

Low and high density cell morphology (200x)

Luciferase Expression

The indicated number of cells were placed in wells of a 96-well plate. After the addition of 3 mg/mL d-luciferin, the plate was immediately imaged using an IVIS Spectrum. The total flux (photons/sec) was plotted as a function of cell number.

iRFP Expression

4T1-Fluc-Neo/iRFP-Puro (red) or isotype control (4T1-Fluc-Neo; grey) cells were fixed with paraformaldehyde and analyzed by flow cytometry (20,000 events).

In Vivo Imaging

4T1-Fluc-Neo cells (Imanis Life catalog #CL020) were injected subcutaneously into the right flanks of female NCR athymic mice. Mice were imaged at day 0 on the day of cell implantation and at day 16 using a Perkin Elmer IVIS® Spectrum system, at 10-15 minutes post intraperitoneal injection of D-luciferin at 150 mg/kg. Tumor size was measured using calipers. Data from a representative mouse (ID#3876) is shown.

*Note: This is not an image from this cell line. 4T1-Fluc-Neo is a cell line generated from the same parental line using the same transduction protocol.

Complete Growth Medium: RPMI supplemented with 10% FBS, 1X Penicillin/Streptomycin, 0.1 mg/mL G418, and 2 µg/mL puromycin.

The addition of G418 and puromycin to the complete growth medium maintains high dual reporter expression over continued passage of the cells. It is highly recommended, especially if the cells undergo multiple passages prior to being used for studies.

These cells should be grown in the indicated medium and passaged when they reach confluency. For routine passaging, cells are recommended to be split at a 1:10 ratio every 3-4 days.

4T1 cells frequently clump during growth. When confluent sections of cells become large (e.g. fill an entire field of view at 10X) the cells should be passaged to minimize cell death. For healthy growing 4T1 cells, this usually occurs when the cells reach 80-90% confluency overall.

These cells are suitable for in vitro and in vivo experimentation. 4T1 cells form primary tumors that depending on the route of implantation, can metastasize to the lung, liver, lymph nodes, and brain post implantation into syngenic BALB/c mice.¹

The Fluc and iRFP transgenes facilitate noninvasive bioluminscent and in vivo and ex vivo fluorescence imaging, respectively, of implanted cells. To reduce background autofluorescence, mice should be fed an alfalfa-free diet for at least a week prior to imaging.

The cells can be amplified in vitro and used to generate additional frozen stocks. Cryopreservation of low passage stocks is recommended. Frozen stocks should be preserved in a designated cryopreservation medium.

These cells were generated via lentiviral vector transduction. The lentiviral vector used for transduction was a self-inactivating (SIN) vector in which the viral enhancer and promoter have been deleted. Transcription inactivation of the LTR in the SIN provirus increases biosafety by preventing mobilization by replication competent viruses and enables regulated expression of the genes from the internal promoters without cis-acting effects of the LTR². Nevertheless, all work with these cells should be performed under biosafety-level 2 (BSL2) conditions by trained personnel. Institutional requirements may permit handling of these cells under BSL1 conditions if certain criteria are met.

References:
¹Pulask and Ostrand-Rosenberg. Cancer Res 1998. 58:1486-1493.
²Miyoshi et al. J Virol 1998. 72:8150-8157.