Examples of Assays - Blood Assay Solutions
1.
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.
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
Fresh 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.
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.
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.