🧬 Molecular Cloning Simulator (2D): Restriction Digest, Ligation & Selection

This 2D companion trades the orbiting Three.js scene for a plain sequence-driven bench: the vector's cloning-site region is the real pUC19 polylinker text, and the donor fragment is a designed sequence carrying two EcoRI sites flanking the gene plus one internal BamHI site — the enzyme dropdown doesn't just relabel an animation, it re-scans both sequences for the chosen recognition site with a real substring search, counts the cuts, and only lets a gene fragment ligate into the vector when a reverse-complement check confirms the two sticky overhangs actually base-pair (or, for the blunt cutter, that both ends are blunt). Because a real pUC19 polylinker carries all four recognition sites once each but the donor fragment only carries EcoRI at both flanks, three of the four enzyme choices genuinely fail to produce a usable insert — exactly as they would on a real bench — and the selection plate then separates true recombinant colonies from ampicillin-resistant background that only re-ligated the empty vector, the same false-positive problem real cloning protocols solve with blue-white screening.