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Lab Times
Biobusiness
6-2012
Kbioscience (UK) revives an ancient PCR technique
Dipping into Water Again?
When Kary Mullis made the polymerase chain reaction work at Cetus Corporation in the early 1980s, he had to add
fresh DNA polymerase with every new cycle. So, Mullis sat in front of the lab bench with a stopwatch and manually transferred the tubes from one water bath to the next. Repeatedly. Nowadays, water bath cyclers are extinct, of
course. Or are they?
S
peaking of the book, Umberto Eco,
Italian novelist and philosopher,
commented that, “like the spoon,
once invented, it cannot be bettered” (Umberto Eco, This is not the end of the book,
Harvill Secker, 2011).
It seems that the world of highthroughput PCR would agree, judging by
the handful of companies that have started selling PCR machines based on water
bath technology. Yes, you heard right. Water baths. And no, this isn’t a 20-year-old
copy of Lab Times.
Systems like the Hydrocycler Thermal
Cycler from KBioscience and the Soellex
Thermal Cycler from Douglas Scientific,
are at heart, a giant water bath. To be fair
to the manufacturers, they are very sophisticated water baths – programmable, computer-controlled, and with their own builtin robot. But a water bath they are. So why,
in an age when the Peltier PCR machine is
to the lab what typewriters used to be to
the office, would anyone go back to water?
Reanimating an ancient concept
Jeffrey Anthony, Marketing Director
for LGC Genomics, KBioscience’s parent
company, is very clear. “It works. It works
better and it works faster”, he argues. “It
may well use an older technology at its
core, but it is highly functional and it does
the job.”
Even if it’s difficult to believe, Anthony is right. There are several good reasons
for doing it the old way. Modern Peltier
PCR machines are locked into the struggle
of making rapid temperature changes and
keeping them stable once achieved. For fear
of stating the obvious, the temperature of
the PCR reaction is controlled indirectly by
controlling the temperature of the environment. So one way of keeping temperature
constant is by placing reaction tubes in a
metal block of high specific heat capacity.
Card io lyn x : do u bl e d r u g p a te n t g ra n te d
Revitalising Blockbusters
T
ake yesterday’s blockbuster and transform it into tomoreases. It managed to attract the equivalent of €2.5 million from
row’s wonder drug. That is the credo of Cardiolynx, a start-up
international investors, one main investor being the Basel life
founded in Basel in 2009. The company was granted the
science start-up agency (EVA), funded by two local Basel banks.
first European patent on one of their products, valsartan dinitrate
Cardiolynx now is now seeking an additional equivalent of €4-17
(CLC-1280), a new type of vasodilator.
million to reach clinical phases I and II.
Cardiolynx intends to use valsartan dinitrate
Ambitious plans
to treat angina pectoris, chest pains due to
Four patent families with a total of six
low blood supply to the heart muscle. Andrug
candidates are expected to be granted
gina pectoris is a very widespread disease
soon.
Among these are nitrates of cilostazol,
amongst elderly people and may even prean
inhibitor
of 3-type phosphodiesterase,
dict heart attacks.
produced
by
Otsuka Pharmaceutical, which
Cardiolynx revives old drugs by adding
also
has
a
vasodilatory
effect. Nitrates of
organic nitrates. Through the action of enpioglitazone,
an
activator
of the nuclear
zymes these chemical groups release nitric
receptor
PPAR-gamma
produced
by Zydus
oxide, which acts as a signal to relax smooth
Cadila,
increases
sensitivity
to
insulin.
These
The drug valsartan, an angiotensin recepmuscles. By adding organic nitrates to the
tor
blocker,
ARB),
dilates
blood
vessels
and
compounds
show
potential
in
the
treatment
vasodilator Valsartan, an angiotensin II reof diabetes type 2.
ceptor blocker marketed by Novartis, the ef- reduces blood pressure. Swiss start-up,
Cardio
lynx,
is
to
pimp
up
valsartan’s
action.
Chairman of the Board Jürg Meier, CEO
fects of both entities act synergistically, says
Dirk
Sartor and Scientific Advisor Armin
Cardiolynx. It has successfully completed
Scherhag
have
worked
in
other pharmaceutical companies prepreclinical trials and showed its vasodilatory effect in two different
viously.
Despite
an
experienced
team and their clever idea of
animal models.
double
effect
drugs,
the
path
through
clinical phases will be long
The company wants to position itself as a developer of drug
Florian Fisch
and
arduous.
candidates in the market of cardiovascular and metabolic dis-
Biobusiness
6-2012
KBioscience’s lab
technician, Swati
Patel, operating
the hydrocycler.
Lab Times
page 43
perature changes inherent in water-bath
technology mean shorter overall reaction
times.
“With four machines running in parallel, we have seen over one thousand plates
done in a day,” boasts Anthony.
So, not surprisingly, the hydrocycler
and its kind are selling to labs where large
numbers of PCR reactions are a key step
in determining laboratory throughput and
efficiency. Example applications include
marker assisted breeding programmes to
develop agricultural solutions that provide
improved crops, as well as high throughput
nucleic acid sequencing to understand genetic diversity.
So if a hydrocycler is going to give me
better results and save me time along the
way, am I going to save money, too? Probably not in the short term: a hydrocycler
will set you back some £65,000 (that is
€82,000).
Photo: KBioscience
Aimed at high throughput
But that block’s very resistance to temperature change works against you when
you want to change the temperature. And
you will want to change the temperature
quickly for two reasons. First, while ramping from one temperature to another you
are in a no-man’s land between two ideal
temperatures, with uncertain effects on the
reaction.
Peltier machines must work hard
“Peltier machines have to work hard to
avoid undershoot and overshoot,” Anthony points out. “Water baths have near-zero ramp time”.
OK, so I have been a bit rash. This is no
steampunk PCR. If you can PCR faster and
better, I am all for that, whatever the technology. After all, I will be travelling home
this afternoon in a car that is basically a sophisticated heat engine – the four stroke
internal combustion engine, in essence, is
a modification of the steam engine. And
if the clever engineers at Citroen who designed my car start screaming about “modification” being something of an understatement, so would the creators of the hydrocycler. And with good reason.
The machine does all the dunking
The hydrocycler has a built-in robotic
system that executes any arbitrary program
set up by the user. PCR plates are loaded
into baskets, and the baskets loaded into
the robot. The machine does all the dunking to order. A laser seals the plates with the
very minimum of heat. This is essential, for
microtitre plates with very small volumes,
where a slight rise in temperature can set
off the PCR reaction too early.
The hydrocycler’s high throughput credentials are impressive. The biggest machine of the range can handle up to 50 or
even 60 plates at a time, and the rapid tem-
But remember, this is aimed at high
throughput applications. Sure, you can get
‘traditional’ Peltier machines for around the
€7,000 mark, but you’d be stuck with doing one plate at a time, not to mention a
narrow range of block sizes to work with.
And if you want a standard PCR machine
that can do more than one plate at a time,
you will have to invest as much as €12,000
or €15,000. Even then you will be lucky to
find a machine that can handle more than
four plates at once, compared to the 32 you
can do with the HC-32.
Hydrocyclers are definitely not for the
small molecular lab – this is productionline PCR.
But there are some drawbacks to using
water bath technology. For every temperature you want to use, you must have a separate bath, and there is a limit on how many
reservoirs you can put into a machine – in
the hydrocycler’s case it is four. And you
can’t have temperature gradients, a feature
offered in other high-throughput PCR machines to speed up optimisation.
But that’s not what hydrocyclers are
built for.
Steven Buckingham