Microfluidic cell culture is widely used to develop biochips and biosensors, culturing and experimenting with cells at the microscale. However, only a very small subset of the existing polymers is currently used in microfluidics. This is mostly due to limitations in reversibility and gas-permeability on the sealant. Hence, the development of a novel bonding technique can enable new applications and uses of plastics in microfluidic cell culture, complementing the omnipresent polydimethylsiloxane (PDMS) for critical applications where harder or non-porous materials are required. The present paper describes a reversible gelatin-based room-temperature method for bonding separate substrates, which enables the sealing of commonly used materials in microfluidics such as thermoplastics, but also elastomers and photopolymers. For most materials, the bonding chip resisted to at least 0.1 MPa. To show the versatility of the described method we bonded microchannels of different sizes, up to 200 μm, and round microstructures.The applicability to cell culture was investigated by culturing colorectal cancer HT-29 cells within the chip. Finally, the cells viability was analyzed by in situ live/dead fluorescence staining. Advantageously, the proposed bonding process is reversible and make possible to tune the permeability of the gelatin layer integrated on chip. This room-temperature bonding method is highly efficient for cell culture in plastic chips, potentially opening new routes for the development of innovative BioMEMS devices.