Mammalian Cell Culture and Transfection in a Low-Cost, CO₂-Independent Environment

Traditional mammalian cell culture requires CO₂ incubation to maintain physiological pH, creating infrastructure costs that limit accessibility. We demonstrate successful HEK293T/17 culture using HEPES-buffered CO₂-independent medium in a repurposed consumer-grade egg incubator, reducing incubator equipment costs by >98% while maintaining viability through 10+ passages. To assess feasibility for recombinant protein production, we performed plasmid transfection with pcDNA3.1(+)-EGFP via electroporation. Fluorescence microscopy confirmed robust EGFP expression within 48 hours. These results demonstrate that mammalian cell culture and genetic engineering for recombinant protein production can be achieved using cost-effective, widely available equipment rather than conventional high-cost laboratory infrastructure.