This document outlines the challenges involved in collecting, processing, storing, and ensuring quality control of biological samples for molecular epidemiology studies. It discusses issues related to sample collection such as timing, stability, and adherence to protocols. Sample processing challenges include time sensitivity, sterility, and record keeping. Sample banking must address issues of physical space, labeling, inventory management, and deterioration over time. Quality control involves following standardized operating procedures and maintaining documentation and traceability of all samples. Future advances may include nanobarcoding and fully automated cryobanking systems. Overall, proper handling of biological samples is crucial for protecting data quality and validity.

1. MPF 604
INSTRUCTOR: Dr. C. Kassanga
STUDENTS: Keziah Maina MHA/E/2015/0005
Tipezenji Sakala MHA/E/2015/0004
Challenges in Collection, Storage
and Processing of Biological
Samples

2. Outline
 Introduction
 Sample collection
 Sample processing
 Sample banking
 Quality control
 Conclusion

3. Introduction
 Molecular epidemiology incorporates
epidemiology principles and knowledge of
molecular events that lead to disease
 It uses the concept of biomarkers to describe the
molecular events characteristic for various stages
between exposure and disease
 A molecular epidemiologic study has various
components

4. Introduction
 Study design
 planning phase
 Define sample type and
biomarkers of interest
 Pilot study; validate
biomarkers, best
conditions and factors
affecting their stability
 Informed consent; for
current, future and
unforeseen use of
samples

5. Sample Collection
 A biospecimen taken by
sampling; a
representative of any
other specimen taken
from the source
 Sources
 body fluids e.g blood,
urine
 Tissues
 Cultured cells
 Exfoliated cells
 Tissue/organ swabs

6. Challenges on sample collection
 Interaction between
study subjects, field
personnel and
researchers
 Establish clear
communication
 Deliver clear
instructions to staff
and study subjects
 Reinforced by written
protocols and
frequent
communication
 Methods of sample
collection
 Invasive vs. Non-invasive
methods
 Timing
 Minute-to-minute/ hour-to-
hour variation
 Metabolic variation
 Pre-clinical disease

7. Challenges on sample collection
 Stability of samples
 Anticoagulants; some
required/better or
contraindicated
 Stabilizing agents; for
unstable biomarkers
 Temperature; depend on
biomarker of interest
 Timing before initial
processing; depend on
components of interest
and their stability
 Sterility; esp for RNA
isolation and cell culture
 Endogenous degrading
enzymes; proteins by
proteases and RNA by
RNAases.
 Shipment; Specific
regulations , packaging,
labeling and
documentation of shipped
goods

8. Challenges on sample collection
 Strict adherence to
protocols
 The larger the study, the
greater the challenge.
 Produce SOPs
 Training of all indiv.
 Ensure strict adherence
 Safety;
 Samples are potentially
infectious
 personnel training on
safety precautions
 Containers/equipment
 For collection,storage
and processing
 depends on the sample
volume, means of
transfer to the
laboratory, cost, storage
efficiency, and intended
analyses
 Paper trail; includes
 collection details (date,
sample number, type
and volume),
 shipping information
(rcp’ts and tracking
nos.) and
 chain of custody forms

9. Sample processing
 Produces a number of
samples to be analyzed
or banked for future use
 Variety of processing
protocols;
 Aliquoting and freezing
 Blood: clot & serum
 Cryopreservation

10. Sample processing cont’nd
 More effective processing, provisions for
(1) isolating large quantities of DNA;
(2) storing high-quality RNA;
(3)using buccal cell DNA, blood clot (or blood
smears)
for genotyping;
(4) separating lymphocyte from granulocyte
DNA/RNA;
(5) making metaphase spreads (useful for many
years);
(6) cryopreserving freshly isolated lymphocytes or
whole blood to be recultured
(7) preparing slides of exfoliated cells

11. Challenges of Sample processing
 Time
 Some biomarkers
may decay soon after
collxn
 Essential to process
asap
 On-site processing for
preservation e.g
aliquoting
 Sterility
 Cells for culture
processing or
cryopreservation(DM
SO, liquid nitrogen)
 Record keeping
 Time schedules and
pre-made tables (#
and vol.)
 *large quantities

12. Sample Banking
 Biological bank or
Biorepository
 Goal is
 Make possible for
future analysis for
currently unknown
biomarkers
 Minimizes research
costs for future
studies

13. Challenges of Sample banking
 Physical space
 Labelling & data mg’t;
effective tracking
 Barcoding
 Inventory
management
system;Electronic
data managment
systems (database)

14. Challenges of Sample banking cont’d
 Natural disasters and
Equipment failure
 Store duplicate
aliquotes in different
physical location
 Deterioration of stored
specimens
 tested on regular basis

15. Examples of biobanks
 European Cancer Bank
 National Cancer Institute
Biobank
 School of Public Health
Biorepository, University
of California, Berkely

16. The Future of banking and
biodepositories
 Nanobarcoding
 DNA strands form barcode-like lattice
 Nanobarcodes composed of cyclindrically-shaped
‘stripped’ metal nano-particles
 Store a lot of information on small space
 Cryobanks
 Samples stored in small plates; many samples
attached to memory chip
 Temperature electronics and robotics
 Completely automated DNA isolation and banking

17. Quality Control
 Overall- system application of optimal
procedures, ensure valid ,reproducible and
accurate results
 International Organisation of Standardization
(ISO) created QMS(quality management
systems) standards
 International Epidemiology Association(IEA)
created GEP(Good Epidemiological Practices)..
Quality assurance in epidemiology studies

18. Quality control cont’nd
 Quality assurance practices include
 SOPs specified for each type of biological
sample(QMS-BS); collection, processing, shipping
and storage
 Document and sample control- ID and tracebility
 Purchases and subcontracting- std. materials used
 Process control- from beginning of study; ID of BS,
steps of collxn, processing, storage, shipment and
analysis

19. Conclusion
 Proper handling of biological samples protects quality
of
specimens and validity of results
 Advances in molecular genetics can only be taken
advantage of if sample quality is assured for already
available and future biomarkers

20. THANK YOU!!!!!