A procedure for the orientation of antibody fragments at the gas-water
interface is described and preliminary results are presented. The met
hod exploits the presence of the reactive sulfhydryl group of a reduce
d antibody fragment which can react with a floating monolayer. Surface
pressure measurements show a strong interaction between the reduced f
ragments and the monolayer. Deposited films are characterised by a flu
orescent immunoassay and ellipsometry and the results indicate that th
e antibody fragments are oriented with a high packaging density.