for Cell-Based Assays
the most critical
for successful immune monitoring projects
Getting blood processing right
can be a significant challenge
Blood collection, shipping
and processing is often the first point of failure for cell based
immunology assays, such as ELISpot, flow cytometric phenotyping and
functional cell based assays.
When these assays are
planned as part of multi-center clinical trials, setting up processes
for collecting processing, shipping, preserving blood incorrectly can
have catastrophic consequences for the outcome of cell based assay
Based on our in-depth
experience over nearly two decades in working up complex cell based
assays in the context of multi-center clinical studies we can help you
implement protocols for blood collection, shipping and preservation that
give you the best chance for success.
Get in touch with us to
get help on
Assessment of assay
objective, collection, shipping and processing plan
Training clinical sites
on cell collection
processing and cryopreservation
Biobanking for cell based
When you plan your clinical
study it is imperative that you qualify your blood
collection, shipping and processing supply chain for your specific assay
read out objective. We can help you design and implement the
most appropriate qualification study that can demonstrate that the
signal quality from your assay results can match your study objective.
What could go wrong?
Here are some common
Amount of blood drawn
in the first instance is too low and/or collection tubes are
Patient health status
is not taken into account when planning for cell numbers to be
processing tube used for assay.
After collection the
correct on-site protocol is not followed for initial sample
Delays in shipping
cells, both at collection site and in transit lead to excess cell
separation and, in case, freezing not done to protocol that is
adequate for study.
Freezing buffers and
volume/cell number ratios are incorrect.
The assay readout
objective is unrealistic in the context of a cell collection /
processing strategy that can be realistically implemented.
The above are just an
illustration of possible failure modes. Typically these lead to far less
cells being recovered than intended and those cells that are recovered
have poor viability and functional performance. Couple this with
challenging read out objectives, such as identification of low
frequency antigen-specific T cell responses, and the study is designed to
fail from the outset.
Planning for workable
studies, especially larger ones will automatically require
implementing quality by design (QBD) collection objectives that are driven by
output performance requirements
of a variety of outcomes from blood processing, even where QBD
protocols are applied. These anticipated distributions should be
coupled to pre-agreed fallback options as to how assays will be
carried out when samples of varying quality and cell number are
What kind of experience
does ProImmune have in blood processing?
(i) pre-processed at the collection site, followed by shipping and cetralized cryopreservation at customer generalist CRO sites,
follwed by further international dry shipper transfer, or
(ii) shipped directly
to ProImmune for processing, cryoperservation and biobanking at ProImmune.
(i) tested at
ProImmune's core laboratories or
(ii) stored and/or
forwarded for testing in accordance with the sponsor's directions
general advice on blood processing based on our experience:
PBMCs should ideally be processed within 4-24h of blood draw. For
some demanding study objectives, 24h may already be too long.
should ideally be drawn into sodium heparin Vacutainers®.
CPT Vacutainers® can be used, but as per manufacturer’s instructions
blood should be centrifuged
immediately after blood draw
– not upon receipt at blood processing facility.
Always plan a qualification study of cell cryopreservation, preferably
in the actual assay readout intended. Often this can be carried out with healthy
donors measuring performance of control responses (such as CEF
Cells should be cryopreserved at a minimum concentration of 10
million cells per mL using a qualified protocol
appropriate for the assay in question
Where possible include positive control donors to run
alongside patient samples in every assay.