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MagMAX™-96 Blood RNA Isolation
Kit
Robust High Throughput
RNA Isolation from Blood Samples
Mammalian whole blood is a widely used tissue for molecular
assays due to abundant genetic information as well as ease and
simplicity of sample collection. RNA isolation from whole blood
is challenging, but Ambion’s MagMAX™-96 Blood RNA
Isolation Kit uses strong denaturing lysis conditions and proteases
to effectively inactivate ribonucleases and remove blood proteins.
MagMAX-96 Blood Technology
For RNA purification, Ambion’s magnetic bead-based MagMAX
technology provides a fast, simple protocol that eliminates the
use of organic solvents as well as problems associated with glass
fiber filter-based methods (e.g., filter clogging and inconsistent
RNA yield). Whole blood (and milk) samples can be processed manually
using multichannel pipettes or adapted for automation to recover
total and viral RNA of high yield, quality, and purity. The extracted
RNA is ideal for downstream molecular diagnostics and gene expression
profiling using quantitative reverse transcription-polymerase
chain reaction (qRT-PCR).
Recover High Quality
Total RNA from Blood
High quality total RNA from human whole blood (fresh or stored
at 4°C) can be easily and efficiently recovered using MagMAX-96
Blood. For example, total RNA (8 replicates from multiple donors)
was isolated using the standard MagMAX-96 Blood protocol, which
involves tissue/cell lysis and magnetic bead sample capture followed
by TURBO DNase treatment. High quality, intact RNA with 28S/18S
rRNA ratios >0.9 (Agilent® 2100 bioanalyzer) was obtained
(Figure 1). RNA yield was determined by A260 with an average
range of 0.31–0.52 µg total RNA from all samples (50 µl
each).
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Figure 1. MagMAX™-96 Blood Consistently Recovers Intact Total RNA from Fresh Blood and Blood Stored at 4ºC. Human whole blood from four different donors was collected into EDTA–Vacutainer® tubes; aliquots were stored at 4ºC for 24 hr. Fresh whole blood was collected from the same donors the following day for concurrent RNA isolation with the samples stored at 4ºC. Total RNA was isolated from 50 µl blood from multiple donors in 8 replicates using the MagMAX-96 Blood Kit, and total RNA (~50 ng) from representative samples was analyzed on an Agilent® 2100 bioanalyzer (A). RNA yield was determined by A260 measurement using the NanoDrop® ND-1000A Spectrophotometer (B).
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Genomic DNA contamination was determined by one-step qRT-PCR
targeting hTBP (human TATA binding protein) and RPII (RNA polymerase
II) mRNAs [(+)RT reactions] and genes [(-)RT reactions]. Total
RNA purified from all samples contained minimal genomic DNA contamination
as assessed by delta-Ct values from qRT-PCR (Figure 2). Similar (+)RT
Ct values of qRT-PCR (hTBP and RPII) using RNA isolated from
fresh blood and blood stored at 4°C were obtained.
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Figure
2. Comparison of Total RNA Isolated from Fresh
Blood and Blood Stored at 4°C in qRT-PCR Assays. Total
RNA (~25 ng) was isolated with the MagMAX™-96 Blood
Kit and was used in qRT-PCR targeting the TATA Binding
Protein (TBP, panel A) and RNA Polymerase II (RPII, panel
B) mRNA [(+)RT reactions] and genes [(–)RT reactions].
Minimal genomic DNA contamination was revealed by the
Ct values of (+)RT and (–)RT reactions. Similar
total RNA yield and quality were obtained from fresh
and blood stored at 4°C (for 24 hr) as demonstrated
by similar (+)RT Ct values.
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RNA isolated from blood stored at -80°C had similar yields but
lower integrity than samples from fresh blood or blood stored
at 4°C (data not shown). RNA degradation may result from hemolysis
during thawing; however, the RNA can still be used for successful
qRT-PCR yielding valuable gene expression profiling.
High Throughput Isolation of Blood
RNA for Veterinary Molecular Diagnosis
The ability to directly use whole blood for total and viral
RNA isolation decreases cross contamination and saves time and
resources. This new kit is designed for high throughput viral
and total RNA isolation of 50 µl samples in a 96 well plate.
The MagMAX-96 Blood RNA Isolation Kit has been used successfully
for total and viral RNA from bovine (Figure 3), porcine, and
ovine whole blood, as well as bovine milk samples, allowing high
throughput viral, veterinary molecular diagnosis.
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Figure
3. MagMAX™-96 Blood Is Easily Adaptable
for Automation. Bovine viral diarrhea virus
(BVDV) infection is a major problem of worldwide distribution
that results in economic losses for the beef and dairy
industries. Blood and milk are ideal sample sources for
BVDV RNA isolation due to the simplicity and ease of
sample collection. BVDV positive and negative bovine
blood samples were aliquoted (50 µl) into separate
wells of a 96 well plate and processed using the MagMAX-96 Blood protocol on a Biomek® 2000
(Beckman Coulter). Control RNA was spiked into each sample well at equal
copy numbers to monitor sample processing consistency of the 96 well
plate. The purified RNA was subsequently used for qRT-PCR targeting BVDV
RNA and control RNA. BVDV target amplification was highly consistent:
average Ct=21.4 ± 0.5. Control RNA amplification was equivalent (average
Ct=28.3 ± 0.4) across the 96 samples. No cross contamination was
observed. Processing a full plate of samples requires ~1 hr.
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The MagMAX-96 Blood protocol permits rapid (<1 hr) total
and viral RNA isolation from blood samples (up to 50 µl)
and is also applicable for viral RNA isolation from milk samples.
The RNA is eluted in a low salt buffer (20–50 µl) and can
be directly used for qRT-PCR.
Scientific Contributors
Angela Burrell, Quoc Hoang, Roy Chris Willis,
WeiWei Xu, Mangkey Bounpheng, Xingwang Fang • Ambion, Inc.
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