ELISPOT Why CTL?

ELISPOT Figure 1

Figure 1: Improvement of IFN-ץ ELISPOT assay results using the ImmunoSpot® protocol. Freshly isolated peripheral blood mononuclear cells were cultured for 24h with media or the recall antigen tetanus toxoid (TT). Note the decreased background and increased signal with the ImmunoSpot® protocol ("New").



At the very heart of science are exact, objective and reproducible measurements (see figure 1). The precise evaluation of even such pristine ELISPOT results is impossible when the spots are counted visually, as shown in the lower right panel of the figure.

By introducing and patenting ELISPOT image analysis, we converted the previously time-consuming and subjective evaluation of ELISPOT results into an automated and objective process.

In over 20 peer reviewed publications we have resolved the following fundamental questions (see reference list):

  • Which cytokine spots are produced by antigen-specific T cells (that are to be measured) vs. those produced by bystander cells (being of no T cell diagnostic value)?
  • What do small vs. big spots mean?
  • Where should the cutoffs be set for minimal/maximal spot size when counting and analyzing the different cytokine ELISPOT results?
  • Are measurements made at single-cell resolution?
  • In what frequency range are accurate measurements made?
  • If there are antagonistic cytokines produced simultaneously, to what extent do they interfere with the results?
  • How many replicates are required to produce significant results?

We Orchestrate the Largest Concentrated Effort Around ELISPOT

Starting from its CWRU based academic roots, CTL has grown to become the world leader in cytokine ELISPOT assay development, automated image analysis, and data management. Twenty-six employees at CTL dedicate their full-time effort specifically to the ELISPOT technology. These efforts are complemented by over 15 academic scientists at CWRU and by close collaboration with the many scientists of BD/Pharmingen.

CTL has been selected as the only ELISPOT reference laboratory by the NIH's Immune Tolerance Network (ITN) to work jointly on the validation of ELISPOT assays for various clinical trials. Dozens of the finest immunology laboratories have entered collaborations contributing invaluable expertise. This alliance constitutes the largest group in the world to further the frontiers of ELISPOT technologies.

The ImmunoSpot® Product Line has Emerged as the Crystallization of Science

We provide scientifically validated ELISPOT analysis equipment, including three analyzer models to meet different user needs and budgets, satellites, accessory software, and data management solutions. In addition, CTL offers image analysis services, ELISPOT wet lab training, image analysis training, and complete contracted research services for clinical trials. Join the community of those who do not compromise in elevating ELISPOT to an exact science!

Many have copied our past accomplishments since we initiated the ELISPOT renaissance. Being the original, CTL is committed to pioneering ELISPOT methods and elevating them to an exact science.