Plasmids are extrachromosomal DNA which is used in recombinant protein production. The project aims to determine the existence of a relationship between the antibiotic resistance of a clone and the plasmid copy number and the expression of the particular protein. The study was conducted on three clones of Escherichia coli carrying a gene of interest. The three clones are resistant to different concentrations of Ampicillin. Expression studies, Plasmid Isolation and Colony PCR are used to determine this. The results of our experiments showed that there was no difference in expression shown by the three clones. Experiments involving Plasmid Isolation and Colony PCR also do not show a difference between the three clones. It could thus be concluded that the antibiotic resistance may be attributed to other factors.