Transcript Field collection and storage

Field Collection and Sampling
courtesy of Carol Ritland
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Starting your collection
• What to sample: Tissue
• What to consider: Age, Season
• What methodology to used for your
biological questions
• What is the natural
history of your organism
eg. Life history etc.
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Starting your collection….cont’d
• Check for permission and necessary
permits for sampling
• Check for location of field sites
• Check on logistics of field collection
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http://www.monkeygrove.com/scribbles/2002/PaperWork.gif
Conifer abundance:
affect on soil richness
courtesy of Carol Ritland
Photos = L. Ritland
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Starfish abundance:
affect on barnacles
Photos = L. Ritland
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1) What should you collect?
2) What could you collect?
3) Where would you collect?
4) When would you collect?
5) How would you collect?
6) How much would you collect?
7) Why did you collect them?
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Tissue (Always go fresh if
possible):
– Plant: Seed, Leaves, Flower, Pollen, Bark, Xylem,
Roots
–Animal: Reproductive tissue, muscle, skin, hair, scat,
blood, ear/toe/tail clip, fin, tooth, sloughed skin, saliva
–Fungal: Hyphae, spores, fruiting bodies
–Bacterial: single isolate culture
–Destructive vs Non Destructive methods
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Factors to consider when
collecting:
• Age:
– Plant = actively growing material such as
apical points, seedlings
– Animal = actively dividing tissue (buccal and
blood cells)
– Fungus = young fruiting bodies (pure culture)
– Bacteria = liquid culture
• Season:
– For conifer = use early spring bud burst
especially for DNA markers
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How to sample:
• Sampling schemes:
– Linear
– Quadratic squares
– Distance between samples
– For animals: migration, reproductive
strategies, life cycle
– For plants: clonality, roots, reproductive
strategies, life cycle
– Consult a statistician? (Gene expression
studies)
courtesy of Carol Ritland
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Sampling cont’d
• Tools for sampling:
– Ideally flash freezing samples with liquid
nitrogen and transportation under ultra low
temperature
– Clean and if possible sterilize collection tools
between samples
– Pack samples with foil or proper containers
eg. cryovials
– Label all samples with non water based ink
and protect with clear tape/paper and pencil
courtesy of Carol Ritland
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Liquid nitrogen vapour tanks
courtesy of Carol Ritland
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Ultralow
temp. Liq
N2 tanks
•Pending on size
•Ultralow temp can last from 10
days to 3 weeks
•Can be used on aircrafts
courtesy of Carol Ritland
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Use sterile
technique when
sampling
•Keep meticulous
records
•Identify any problems in
the field for given
sample
•Do not depend on your
memory alone
courtesy of Carol Ritland
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Long Term Storage:
– Ideally all tissues should be kept at ultra low
temperature (minus 70 to 80°C)
– Certain tissues (blood, animal tissues cut into
small pieces <1mm2 ) could be stored in
100% ethanol and saturated EDTA
– Plants (small amounts) could be desiccated
with lots of silica beads with lots of changes of
beads
courtesy of Carol Ritland
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No No..s
• Items to avoid:
– Unnecessary chemicals eg. Formalin
– historical samples that has been treated with
fixatives
– degraded samples
– freezing and thawing of tissue
– freezer burn (improper storage conditions)
– improper inventory of samples
courtesy of Carol Ritland
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More to ponder…..
• Items to consider:
– For certain molecular marker (eg. AFLP,
microarray) use the same tissue type
(developmental differences could cause error
when genotyping)
– If possible collect all samples within a season
over a same span of time (eg. For microarray
analysis)
– Collect more samples than required for pilot
study and lost of samples
courtesy of Carol Ritland
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