Identifying the origin of single corneal cells by DNA fingerprinting - Part I - Implications for corneal limbal allografting

Purpose. To demonstrate that the combination of impression cytology and sin gle cell DNA fingerprinting represents a powerful tool that is suitable for detecting transplanted cells after corneal limbal allografting. Methods, F ifty single cells were obtained by corneal impression cytology from 12 pati ents undergoing cataract surgery. Individual cells were isolated from sampl es by micromanipulation. Polymerase chain reaction and short tandem repeat profiling was used to obtain forensic standard "DNA fingerprints" from sing le cells. Blood samples taken at the time of impression cytology provided c ontrol "fingerprints. Results, informative DNA fingerprints were obtained f rom all corneal samples and 66% (33 of 50 cells) of isolated single cells, Of all fingerprints obtained, most (91%, 30 of 33 fingerprints) corneal fin gerprints matched corresponding blond sample fingerprints. At least one cor neal fingerprint matched the corresponding blood sample fingerprint in 83% (10 of 12 patients) of the patients in the study, Conclusions. This extreme ly specific single cell DNA fingerprinting system permits accurate identifi cation of individual corneal epithelial cells, allowing very reliable deter mination of their origin, which will enable host and donor cells to be dist inguished from each other after keratolimbal allografting procedures. even if the host and donor are the same sex or siblings. These DNA fingerprintin g methods allow assessment of quality and quantity of donor cell survival, as well as survival time. The extreme sensitivity and accuracy of the techn ique means that should contamination occur, it would be identified, thus en suring meaningful results.