Tissue Sampling and
Storage
Sampling for Molecular Systematics
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Research in molecular systematics requires
plasmid, cell or tissue samples in which
proteins and nucleic acids are maintained in
intact physically active state.
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Materials are normally collected from field,
therefore a proper planning is needed to ensure
the good condition of the samples.
Regulations governing acquisition of
specimens
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Collectors should become familiar with local
state, national and international laws and
regulations, and they should allow adequate
lead time to obtain the necessary permits.
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Scientific collecting permits/permissions
usually are necessary for sampling natural
populations and protected species.
PERHILITAN; Jabatan Perhutanan Negeri;
Jabatan Perhutanan Semenanjung Malaysia;
Sabah Parks; Sarawak Biodiversity Centre etc.
Documentation of Samples
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Label samples and specimens so that no
information is lost in wrapping, transport,
storage, and entering of data into permanent
records.
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Field collection data (location, habitat,
behaviour, whether, date) is important.
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Prepare voucher specimens (herbarium,
museum etc.) for the purpose of crossreference.
Sources of Sample
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Fresh materials can be obtained from field.
Animal
blood, tissue (organ, muscle …), hair (follicle),
bone, skin, egg etc.
Plant
leaf, flower (petal), inner bark tissue (cambium),
twig, pollen, spore (fern) etc.
Sources of Sample
Alternative sources
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Museum collection (animal samples)
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Herbaria (plant samples)
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Tissue/organ collection preserved in paraffin
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Protein extract from the isozyme analysis
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Tissue in microscopic slide
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Fossil/archeological material (degraded DNA)
Preservation of Samples
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Proper sample preservation in field is crucial for
molecular systematic study.
Cryoperservation - use of liquid nitrogen
Alcohol or formalin - mainly for animal tissues
where tissues are cut into small pieces and
soaked in 95% ethanol
Buffer/salt solution – plant/animal tissues are
cut into small pieces and soaked in DMSO
(dimethyl sulfoxide; for animal) buffer or CTAB
(cetyltrimethylammonium bromide; for plant))
buffer
Preservation of Samples
Silica gel – plant tissues are cut into small
pieces and put into container containing silica
gel
other methods – leaf samples are wrapped with
moist tissue paper before putting into plastic
bag; add anti-clotting agent (EDTA, heparin) to
blood plasma sample.
Storage of DNA/protein samples
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Protein/isozyme always stored at -20C (freezer)
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DNA sample may be stored at 4C (fridge) or 20C (freezer)
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For long term storage, DNA/Protein need to be
kept at -70C (freezer)