M-1

The M-1 cell line is a well-characterized epithelial model derived from the kidney of a transgenic adult mouse. Specifically, M-1 cells originate from the cortical collecting duct epithelium and retain many differentiated features of this nephron segment. These cells express markers typical of cortical collecting duct cells, including epithelial sodium channels (ENaC), aquaporins, and tight junction proteins, making them a widely used in vitro model for renal physiology, ion transport, and epithelial polarity studies.

Functionally, M-1 cells exhibit high transepithelial resistance and vectorial ion transport properties, which are critical for studying aldosterone-regulated sodium reabsorption and vasopressin-mediated water transport. According to the foundational characterization by Stoos et al., M-1 cells form polarized monolayers on permeable supports and show appropriate responsiveness to hormonal stimuli, such as dexamethasone and aldosterone, that regulate transport protein expression and activity. These features make M-1 cells particularly valuable in dissecting mechanisms of electrolyte handling and cellular signaling in kidney epithelial cells.

Moreover, M-1 cells have been validated in more recent studies, including genetic authentication using STR profiling for mouse cell lines. This underscores their continued relevance and reliability in contemporary renal physiology research. Their ability to recapitulate in vivo-like behaviors under controlled conditions has established them as a standard in studies on epithelial function, nephrotoxicity, and renal disease modeling.

37°C, 5% CO₂, humidified atmosphere.

1. Confirm that the vial remains deeply frozen upon delivery, as cells are shipped on dry ice to maintain optimal temperatures during transit.

2. Upon receipt, either store the cryovial immediately at temperatures below -150°C to ensure the preservation of cellular integrity, or proceed to step 3 if immediate culturing is required.

3. For immediate culturing, swiftly thaw the vial by immersing it in a 37°C water bath with clean water and an antimicrobial agent, agitating gently for 40-60 seconds until a small ice clump remains.

4. Perform all subsequent steps under sterile conditions in a flow hood, disinfecting the cryovial with 70% ethanol before opening.

5. Carefully open the disinfected vial and transfer the cell suspension into a 15 ml centrifuge tube containing 8 ml of room-temperature culture medium, mixing gently.

6. Centrifuge the mixture at 300 x g for 3 minutes to separate the cells and carefully discard the supernatant containing residual freezing medium.

7. Gently resuspend the cell pellet in 10 ml of fresh culture medium. For adherent cells, divide the suspension between two T25 culture flasks; for suspension cultures, transfer all the medium into one T25 flask to promote effective cell interaction and growth.

8. Adhere to established subculture protocols for continued growth and maintenance of the cell line, ensuring reliable experimental outcomes.

Mycoplasma contamination is excluded using both PCR-based assays and luminescence-based mycoplasma detection methods.

To ensure there is no bacterial, fungal, or yeast contamination, cell cultures are subjected to daily visual inspections.

For long-term preservation, place vials in vapor-phase liquid nitrogen at about −150 to −196 °C. Storage at −80 °C is acceptable only as a short interim step before transfer to liquid nitrogen.

Cryopreserved cell lines are shipped on dry ice in validated, insulated packaging with sufficient refrigerant to maintain approximately −78 °C throughout transit. On receipt, inspect the container immediately and transfer vials without delay to appropriate storage.

At Cytion, we stand behind the quality and viability of our products. We guarantee that our cells will be viable at the start of culture for 60 days after shipment from our facilities. We assure that all materials conform to the specifications described in the Certificate of Analysis and/or Product Sheet.

For full details, please refer to our Warranty Statement.