Quality Control

The I.M.A.G.E. Consortium maintains the largest public cDNA collection in the world. These clones provide a major resource for many biological applications, including gene discovery and gene expression studies. For instance, microarray technologies rely on large number of ESTs to monitor the changes in gene expression under varying conditions. For all of these applications, it is vital that the clones, which provide the foundation for the experiments, accurately represent the sequence that is submitted to the database.

Recently the Consortium has received reports of sequence errors ranging from 10% to 30%. (Note, a clone has a sequence error when the sequence obtained from the clone does not match the sequence reported in dbEST.) A significant effort needs to be undertaken to determine the true error rate(s) and the source of the errors, and to preserve the high quality of the I.M.A.G.E. Consortium data and clone set. Based on the findings, changes may be implemented throughout the process to reduce these errors.

With the support of the I.M.A.G.E. Consortium distributors, we intend to determine the current error rates for I.M.A.G.E. Consortium clones and sequences, characterize the sources of discovered errors, and implement continuous quality control measures that will provide early detection of significant changes in the clone replication and distribution process.


  1. Determine the sequence error rate of the existing I.M.A.G.E. Consortium cDNA collection at key stages of the replication and distribution process.
  2. Design and implement quality control measures at key points of the process to identify future sequence errors.
  3. Provide the public with the I.M.A.G.E. Consortium quality control plan, current and historical error rates at key points of the process, and "fixes" to sequence errors where possible.