Figure 3

Trapping of secreted proteins. ELISA was used to detect secreted epitope-tagged protein in the media. Position number 4 in this case identifies a significantly high signal. Following the screening of total 5,670 clones, two clones gave significantly high ELISA signals. One was identified as plasminogen activator I (PAII). However, the other clone failed to yield consistent sequencing result following the 3'-RACE reaction. Thus the protein identity of this second clone remains unknown.