Adhesion of dissociated mouse embryonic brain cells. A new method of quantitative evaluation

The adhesion of mouse embryonic brain cells was measured in a rotating chamber. A method is proposed for quantitative evaluation of adhesion kinetics. Dissociated cells were incubated in a planparallel chamber and pictures were taken between time 0-120 min. Film negatives were evaluated by computer--controlled scanning. Ten thousand individual data area obtained from one frame and 1,000 levels of absorbency are distinguished. A method is described which allows the discrimination of area, density and the shape of adhering cells. The influence of the dissociation procedure on cellular adhesion was studied. Short trypsinisation (0.025% trypsin for 5 min) followed by sieving was most favourable for adhesion. Mechanical sieving and dissociation with EGTA (Ca2+ chelator) gave less satisfactory results. Significantly diminished adhesion was observed after prolonged trypsinisation. If cells were incubated in media lacking Ca2+, adhesion was significantly inhibited. The kinetics of adhesion follows the curve of flocculation kinetics independently of the dissociation procedure and composition of the medium.