Improved Procedure for Screening Expression Libraries for Novel Autoantigens

Abstract

The standard method for immunoscreening of a cDNA expression library is time-consuming because<br />of the production of a large proportion of false positives during the first and second round of screening.<br />This problem is more important when a sensitive chemiluminescence detection system is used. Due to<br />the high sensitivity of the detection system, there is a need to avoid false positives which occur when the<br />antibody reacts non-specifically. False positives are generally eliminated through absorption of the antibody<br />with the host bacteria and by eliminating any clones, which react with antibodies present in normal<br />sera. Here we present a method of obtaining almost identical bacteriophage plates by culturing phage in<br />parallel, and show that this technique produces positive plaques in duplicate and eliminates false positives.<br />Using this method, we successfully screened a human fetal spinal cord lambda gt11 cDNA library<br />using purified immunoglobulin G (IgG) from patients with multiple sclerosis (MS) and Guillain – Barre syndrome (GBS).<br /><br />