Blood Assay Solutions

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Examples of assays

1. IC50 comparison on multiple donors

Compound A has been found to inhibit LPS-induced TNF release. IC50 will be measured in whole blood assays to assess donor to donor variation.

Assay design: fresh whole blood from 8 different donors is preincubated with increasing concentrations of compound A and treated or not with LPS. After 4h incubation, TNF is measured in the supernatants.

 

Plate layout and results (for illustration only)

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Conclusion: compound A inhibits LPS-induced TNF production in all the donors tested. IC50 ranges from 1.5 to 10µM.

2. Detection of contaminants

The purification of compound B comprises several decontamination steps to remove contaminants of bacterial origin. A whole blood assay is used to validate the removal of contaminants after each purification step.

Assay design: whole blood from 2 donors is incubated with serial dilutions of compound B sampled after each purification step. After 4h, IL6 is measured in the supernatants.

 

Plate layout and results (for illustration only)

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Click for full size image


Conclusion: The final product is free of contaminants.

3. Comparison of different adjuvant formulations

A vaccine company wishes to evaluate different formulations of an adjuvant.

Assay design: fresh whole blood from 3 different donors is incubated 4-6h with serial dilutions of each formulation. The release of pro-inflammatory cytokine(s) (e.g. IL1, IL6, TNF) is then measured.

 

Plate layout and results (for illustration only)

Click for full size image

Click for full size image


Conclusion:

  • Formulation #1 doesn’t induce a response in any of the donors.
  • Formulation #3 is as efficient as the positive control.
  • Formulation #4 is less efficient than formulation #3.
  • Interestingly, formulation #2 works in donor A and C but not with donor B reflecting donor to donor variations specific to this formulation.