Quantification of the nonspecific intercellular transfer of fluorescent molecules between labeled and unlabeled rat thymocytes

Open Access
Publisher Website
Google Scholar
Abstract
Fluorescein isothiocyanate has been used to label normal or tumor cells in order to study their migration in vivo. This requires that any transfer of fluorescence to neighbouring cells be carefully ruled out. The aim of the present report is to demonstrate the possibility of a transfer of fluorescein or fluorescein-bound molecules between untreated and labeled cells. When normal rat thymocytes were co-incubated with labeled cells (about 5 × 106 fluorescein molecules/cell) under continuous agitation or exposed to supernatants of these labeled cells, they bound an average of 104 fluorescein molecules. When the incubation was done on cell pellets after centrifugation, this transfer was increased tenfold. Hence, intercellular molecule exchange may occur in the absence of any specific interaction.