Jim,
Have you done a sham coat to assure that your signal is specific? Run at
least 20 sera from normal patients to determine what your natural
background is in the assay. Second, spike your antigen (purified) into the
patient's serum and see if you can block antibody binding to the plate.
These experiments should help answer your questions.
Tom Parish
Bioassay Dept.
Biogen, Inc.
Email: Tom_Parish at Biogen.com
To: immuno @ net.bio.net @ internet
cc: (bcc: Tom Parish/Cambridge/Biogen)
From: jlk1117440 @ aol.com @ INTERNET @ WORLDCOM
Date: 04/14/97 05:31:02 PM CDT
Subject: ELISA question
I have performed an ELISA to detect patients' reactivity with a naturally
occuring protein (about 28 kDa). Now I have optical density readings of
the plate, but am not sure if the numbers are significant. For example,
if one patient's reading is .250 and another's is .050, is the former
positive and the latter negative? I would appreciate any help.
Jim Knoetgen, MD
St. Luke's - Roosevelt Hospital Center
New York, New York