00:00 Wide,
National Blood Service Centre & Sign, Bristol
c.u.
National Blood Service sign & logo
Wide,
National Blood Service testing laboratory
c.u.
blood samples
Wide,
Lab Tech placing samples in rack
c.u.
placing samples in rack
Wide,
Technician transfers rack to analysis machine
c.u.
samples going into analysis machine
Medium
wide, analysis in progress
Closer
of above
Analysis
plate appearing in viewing window
c.u.
U.W.E Faculty of Applied Sciences sign
Wide,
Researcher loading Bloodgen chip in scanner
c.u.
of above
Screen
shot of blood chip results
Wide,
Researcher at computer, Prof. Avent enters
2
shot, Prof. Avent and Researcher
Prof.
Avent
c.u.
Researcher
Guide Voice: Few of us pay much attention to
the subject of Blood transfusion. It’s something we hope we
never need but expect to be there if we do. In most developed
countries safe blood transfusion is often taken for granted and few
of us would give much thought to the complexities of blood grouping
and blood transfusion.
But it is a complex issue. Not all blood groups are compatible
with each other and mixing incompatible blood groups leads to blood
destruction, which can put some people at risk. Current tests for
blood grouping are based on Blood group serology, a technology that
has been in use since the very early days of blood transfusion. Two
tests are routinely done - for blood groups ABO and Rh.
Now Bloodgen, a consortium made up of many of Europe’s
experts on molecular blood grouping and funded by the European
Commission, is nearing the end of a three year research project
into genotyping, aimed at improving patient safety &
blood transfusion compatibility.
Led by Professor Neil Avent at the University of the West of
England in Bristol, their novel approach to developing a testing
strategy for blood grouping compatibility means that health
professionals now have a chance to test routinely for 9 blood group
systems instead of the two covered by serology testing.
01:11 SOT: Professor Neil Avent, Director of the Centre
for Research in Bio Medicine, Faculty of Applied Science,
University of the West of England, Bristol –
“Blood grouping at the moment uses antibodies that
interact with proteins on the surface of cells. Genotyping is
looking at the genes, the genetics. We all have DNA and that DNA
can be extracted and analysed and we’re looking at blood
group specific genes which vary from one individual to another. By
devising our molecular based test we can look at individuals’
blood groups; differences in single nucleotide changes, for
example, generate blood groups so the testing strategy we have
enables us to do that.”
01:44 c.u.
applying bar codes to Bloodgen chip
Wide
of above
c.u.
Researcher’s face
c.u.
Bloodgen chips in machine
Wide
of above, lid closing
Wide
of laboratory
screenshot
of chip analysis
c.u.
of above and pan
Wide
of screen with results
Guide Voice: The differences in human blood are
due to the presence or absence of certain protein molecules -
antigens and antibodies. The antigens are located on the surface of
the red blood cells and the antibodies are in the blood plasma.
Individuals have different types and combinations of these
molecules and the blood group you belong to depends on the
combination of antigens built into your DNA and antibodies to
antigens you have previously been exposed to.
The genotyping tests are carried out by extracting DNA from a
donor’s blood, fragments of the genes that are involved in
blood group antigen expression are then amplified by a process
known as the polymerase chain reaction and hybridised to a specific
gene chip - a small microscope slide containing synthetic DNA. The
resulting interaction enables the genotype to be established based
on differences in fluorescent intensity, a strong fluorescence
would indicate a positive for a particular blood group, weak
fluorescence a negative.
02:37 SOT: Professor Neil Avent, Director of the Centre
for Research in Bio Medicine, Faculty of Applied Science,
University of the West of England, Bristol –
“This is certainly a safer means of testing
blood because of its comprehensiveness. There are certain blood
groups that are not routinely tested for by blood banks – for
example, some of the kidd system is not routinely tested for
– so the bloodgen chip will embrace all blood groups that are
clinically significant and we’ll be able to have those tested
on a routine basis.”
03:01 Wide
of Research Lab, Researcher enters shot
c.u.
researcher’s face
c.u.
samples entering analysis
machine
Guide Voice: Though serological testing is
inherently safe, routine testing doesn’t cover all clinically
significant blood group antigens because it’s not practical
or economic to test every blood donation for every blood group.
03:12 SOT: Prof. Avent – “The
ultimate goal for me is to see a sea change in blood grouping. So
that a new technology will come in and, hopefully one day, replace
the original technology of blood group serology, which has been
around for 100 years or so. I think genotyping’s incredibly
accurate and it’s much more comprehensive than blood group
serology. Certain serological reagents are not available, they can
be very expensive; genotyping as a core technology will only go
down in price within the next ten years or so. So although the
tests, per se, at the moment are relatively expensive the net costs
per test within the next decade are going to drop very
significantly. So I think genotyping is going to be used for a wide
range of routine testing of patients in the near
future.”
04:03 End
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