When polymeric molecules squeeze through a nanometer-sized pore in membranes, in a process known as translocation, they leave a distinct signature at the pore. Present-day techniques can exploit translocation to recognize individual polymeric molecules by analyzing these signatures. Interestingly, one encounters translocation more frequently as a serious bottleneck: the prospect of polymeric molecules passing through nanometer-sized pores in inter/intra-cellular membranes hinders efficient delivery of drug molecules to their activation sites, and of healthy gene fragments to their target sites in gene therapy.