Hi, my name is Lauri and we're going to talk
a little bit about synthetic biology
and high throughput methods on how to create biosensors.
We human beings are really bad at sensing
weak signals in nature. We cannot see buried landmines,
we cannot smell polluting chemicals in nature,
we cannot taste toxins in our drinking water.
We have created really, really sophisticated
analytical methods to detect all of those things.
But those instruments are really expensive
and next to impossible to use in field.
For example, arsenic is a really common element in the soil,
but when it leaks into our drinking water, it becomes
a tasteless and odorless killer.
In western world, we can do analysis on our drinking
water and monitor the levels of arsenic.
So you can be pretty sure that the water you're drinking
is safe, but in the developing countries,
those instruments are not available.
The water is taken from wells and all the laboratories
are far away. So what we would need is a simple
kit that would be really cheap and easy to use,
that anyone can use to monitor the levels of arsenic
in their drinking water.
Now, what analytics is all about is
taking a weak signal and converting
it into something that we can see,
or detect. Microbes have evolved into
sensing their environment and reacting upon
it. So, if we could use the microbe to take
the input signal and turn it into something visible, like
light. That would be really handy
and you would call that a biosensor.
And now, the structures in the microbe that would do it
would require some part that takes the input signal
and then launches some kind of output signal.
This, we would call a reporter gene.
Reporter genes should be very sensitive,
it should detect really small amounts of the input signal
and it should also be very specific.
It should not react to just anything. Now
let's take a quick closer look into this promoter
part of the reporter. We could cut it down in smaller
parts, some of the parts would be responsible for binding
transcription factors, some other parts would be
responsible for binding polymerases,
and some other parts would be responsible for
binding ribosomes. There would also be some linkers
that would space those elements from each other.
Now we can rationally decide these parts.
Building all different kinds of variations,
and then combine them together into different
kinds of combinations. Now, we would pretty soon run into
a problem that we have many of these combinations
and that would result in a huge number of
samples that we should test. Essentially, that would
result in a huge number of microbes that we need to test
for, for their ability to function as a biosensor.
And that is something we can do with robotics.
Hi, my name is Angela. So in this experiment, we are
going to test different promoter constructs.
Since we are dealing with a huge amount
of different possibilities, we need to be assisted by
a robot to make it feasible. So basically, what the robot
will do for us is to introduce the different promoter
constructs into the bacteria. Then, we will test
the promoter activity by measuring the cell's luminescence.
Hi, I'm Claudia and in this experiment
we are interested in identifying a mutant
which shows stronger activity than the other potential candidates
strains to finally create a more efficient promoter.
So when we looked at the data, we saw
that if you completely destroy the promoter, you don't see any
activity, which is measured illuminescence compared to a white background
of potential strains which show relatively low
and comparable activity.
However, we were able to identify
one particular strain which showed very strong illuminescence
and is therefore a potential candidate for
further experimental follow-up.
Synthetic biology not only gives us the tools to create
all those combinations, but more importantly, allows us
to select from a huge amount of variation.
In this case, we could select the one microbe that
does the job for us, pick it from the sample,
and trace back the combination of elements that we
actually used to make it. In this case,
this specific combination allowed sensitive and very specific
detection of the input signal and a very
dynamic output signal. Now, this might
microbe could be used to create a sensitive,
cheap, and easy to use tester to make sure
that your drinking water does not contain arsenic.
This is not science fiction, this is done already
in several companies developing this technology.
Synthetic biology allows us to create these
biosensors for practically anything.
