Module 9 2021

24/03/2021

Measurements in bioassays - Variation of ED 50

response

assay 1

ED 50

ED 50

assay 2

Example: ED 50 of JNIH-5 pertussis toxin in CHO cell assay: varied about 1000-fold across all assays in a multi-lab study (Xing et al, Vaccine 20 (2002) 3535 )

The Organisation for Professionals in Regulatory Affairs

15

15

Measurements in bioassays

• Activity of a new batch of therapeutic measured against a defined Reference standard material

std

std

unk

unk

• If the new batch and standard are sufficiently similar, variations in the assay system affect them both and therefore quantification is measured as Relative Potency

The Organisation for Professionals in Regulatory Affairs

16

16

8