Growth kinetic studies (in hours) based on the fluorescence of stable, GFP-expressing CHO cells

摘要

This study correlates the fluorescent signal from a stable CHI cell line expressing the Green Fluorescent Protein (calcium phosphate cotransfection of CHO DG44 cells with l:20w/w linearized pEGFP-N1 from Clontech and a DHFR vector) with viable cell number, extending the use of fluorescent proteins to kinetic applications. This cell line has maintained its GNP expression over months without selective pressure (data not shown). Using a standard fluorometer, growth of these cells can be quantified noninvasively in multiwell plates, and since signals are obtained without preparation, the same culture samples can be measured repeatedly. In this way, the dynamics of cell growth can be studied with high sensitivity, low error rate and minimum sample preparation and on a time scale practically impossible with traditional methods. It is thus possible to identify and to follow growth trends without counting cells.