One big challenge in antibody engineering is to satisfy expression levels, stability and affinity requirements of the engineered antibodies.Currently no such platform was available to address the issue.We devised a technology, FAst Screening of Expression, Biophysical-properties and Affinity (FASEBA), which provides expression, biophysical property and affinity data on a large number of candidate proteins at very early stage of development without protein purification.A protein anchor BSA12, which has a low picomolar affinity to BSA yet this binding can be easily disrupted, plays a key role in the development of the FASEBA technology.We present here how this platform can be used to engineer antibodies to screen functional antibodies and antibody fragments including single chain antibody (scFv), antigen binding fragment (Fab), IgG and camelid single domain antibodies (sdab).Engineering of camelid single domain antibodies are specially discussed to emphasize their excellent drugability based on their small size and good stability fetures.