CPACT Webinar on
APIES (simultaneous Absorbance, Polarised
Intrinsic Emission, and Scattering): a robust multi-attribute measurement system for biopharmaceuticals
Alan Ryder, University of Galway
26th November 2026 at 3pm (UK
time)
Analysis of intrinsic fluorescence emission provides
a label-free, non-destructive, and sensitive method for measuring quality
attributes that is suitable as a biopharmaceutical Process Analytical
Technology (PAT). The full fluorescence
emission space, captured using Excitation Emission Matrices (EEM), when coupled
with multivariate data analysis provided a convenient analytical method for
cell culture media [1] and bioprocesses [2].
Extending EEM with using UV transparent polarizers [3] enabled higher
resolution polarised intrinsic emission (PIE) measurements of proteins which
have been used for protein quality analysis [4], antibody-drug conjugate (ADC)
reaction monitoring [5], and protein quantification [6].
A simpler and more robust derivative is APIES:
simultaneous Absorbance, Polarized Intrinsic Emission, and Scattering
measurements which is a rapid (<1 min.), robust measurement system. APIES provides three orthogonal process data:
protein concentration, degree of aggregation, and structural integrity. This is easily implemented using a
multichannel fluorometer fitted with UV transmitting polarizers and either
standard quartz cuvettes (at-line) or quartz flows cells (online) [7]. We used APIES monitoring of low pH (3.4-3.8)
Viral Inactivation (VIN) of IgG proteins under different pH conditions [7]. APIES both quantitatively tracked in-situ
aggregation and also potentially discriminated between reversible and
irreversible aggregates formed in-situ.
SEC did not observe the formation of the reversible aggregates in the
reactor. In a second case study, we used
APIES for real-time monitoring of protein-liposome interactions [8] and here,
using a simplified single excitation wavelength, we obtained a temporal
resolution of 1 second. This allowed the
three phases of interaction (adsorption, penetration, and annealing) to be easily
monitored. Further work in my lab is
ongoing to demonstrate the efficacy of APIES for ADC reaction and stability
monitoring, downstream processing of mAbs, analysis of high concentration
protein formulations, and cell culture media analysis.
In conclusion, APIES
is a fast, inexpensive, and efficient PAT ready measurement system for the
downstream processing of biopharmaceuticals.
References:
1)
Li, B.; Ryan, PW.; Shanahan,
M.; Leister, KJ.; Ryder, AG. Appl. Spectrosc. 2011, 65, 1240.
2)
Li, B.; Shanahan, M.; Calvet,
A.; Leister, KJ.; Ryder, AG. Analyst 2014, 139, 1661.
3)
Casamayou-Boucau, Y.; Ryder,
AG. Methods Appl Fluoresc 5, 037001, (2017).
4)
de Faria e Silva, A. L.;
Elcoroaristizabal, S.; Ryder, AG. Anal. Chim. Acta 1101, 99-110, (2020).
5)
de Faria e Silva, AL.; Ryder,
AG. Biotechnol. Bioeng. 119, 3432-3446,
(2022).
6)
Boateng, BO.; Ryder, AG. Anal.
Chim. Acta 2026, 1383, 344894, (2026).
7)
Zang, JD.; Ryder, AG. Analytical
Chemistry, 98, 26, 19533–19544, (2026).
8)
Wang, H.; Ryder, AG. Nanoscale
18, 11510 - 11524, (2026).
This webinar will take no longer than one
hour.
The webinar is for CPACT members only and
is free to attend.
Please register at
https://universityofstrathclyde.webex.com/weblink/register/rc05967b9f79ec8d3d068e13c108c2ec9