The cellular enzyme-linked immunosorbent assay (CELISA) permits assay
of cell surface antigens on intact fixed cells. Using a monolayer of c
ells cells as the solid phase, the CELISA offers an inexpensive altern
ative to Slow cytometry. In addition, this protocol has the decided ad
vantages of miniaturization (small numbers of cells) and ease of repli
cation (the 96-well cluster plate format). In efforts to optimize CELI
SA for detecting surface antigens on human fibroblastlike synoviocytes
, the authors found that cell number, serum proteins, choice of cultur
e plate, pipetting technique and fixatives may all impact the results
of the CELISA.