CHO-CEACAM1-4L transfectants adhere preferentially to immobilized recombinant human CEACAM1-3-Fc and CEACAM1-4-Fc domain deletion variants.

The 96-well Immulon 3 plates were coated with goat antihuman Fc prior to the addition of the CEACAM1-1-Fc, CEACAM1-3-Fc, and CEACAM1-4-Fc soluble proteins. CD31(D1-3)-Fc, MUC 18(D1-5)-Fc CD14-Fc, and NCAM(D1-7)-Fc were used as negative control constructs. CHO transfectants were labeled with the fluorescent tag, BCECF-am, and allowed to adhere to these soluble constructs for 60 minutes at 37°C. The total fluorescence of each well was then determined using the Cytofluor II fluorescence plate reader. The plates were then washed and the number of cells adhering determined by fluorescence estimations in the Cytofluor II as a percentage of the total cells added per well.