How to keep the flytrap alive during the experiment?

In it's original pot the flytrap was too tall for the x-ray machine so we couldn't put the whole plant in. To solve this problem, I transferred the plant into a much shallower dish. I dug the plant out of the original pot by running a dinner knife around the edge. I carefully tipped the pot sideways until the plant began to slide out of the pot. The moss around the plant helped to hold the soil and plant together. The roots of the flytrap were very short and did not reach very far into the pot. I tipped the remaining soil from the terracotta pot into the shallow dish and then placed the flytrap on top. I gently patted the soil in around the plant.

Once the plant was in the new dish I carefully watered it. I have to add the water gradually now because the dish is so shallow it is very easy to pour on too much and then it flows over the edge of the dish making a lot of mess!

I hope the plant will survive the transfer to it's new home.

I cut a short piece from a drinking straw and placed it around one of the stems. This was quite a fiddly job. I had to be very careful not to damage the plant. I accidentally touched some of the traps near the base and they closed. They should open again in a few days when they realise they have been tricked! The drinking straw holds the stem up, keeping it vertical. This is not natural for the Venus flytrap but it will make it easier to x-ray an individual trap.

What settings should be used on the x-ray machine?

The flytrap that Julia gave me had some traps that were already closed. Sharif and I decided to carry out a test scan with one of these to find out what settings the x-ray machine needed and what we would be able to see.

In the x-ray machine you have to place the sample, the thing you want to x-ray, on a stage. Our first problem was that the pot containing the flytrap was too tall. The stage could not be lowered enough to get the leaves the flytrap in front of the x-ray source (this is where the x-rays are shot out from towards the sample).

As a solution, I cut off a trap that had caught a fly. We could see one of the wings sticking out of the top! Sharif placed the stem inside a short piece of a drinking straw and carefully packed in some oasis. Oasis is a foam which holds water, it is used by flower arrangers. It would help to keep the stem still while it was being x-rayed.

Sharif placed the straw in a sample holder and put it in the machine. It was now the right height. Sharif set up the machine and scanned the sample. Although this will give us an image to look at, the trap I cut off will die, so we won't be able to use it again.

Now we have to wait for the results. We also have to work out how we can put the whole plant in the scanner so we don't have to cut off a stem to put it in the x-ray machine and keep it alive so we can scan it multiple times.

Day 2 - Scanning Trip June 2016

We worked through the night scanning samples. This morning we began the second experiment. For each sample a sweetcorn seed, which has been germinated - this means it had started to grow a root, is stuck to a plastic fitting using plaster of paris. The root is fed through a hole in the fitting so a little bit sticks out the end. A syringe barrel filled with soil is then attached to the fitting and the whole thing is put in the scanner. We are scanning the root every 6 minutes so we can see how it interacts with the soil particles as it grows.

So far the experiments have been running pretty smoothly and we have been seeing some good results.

Day 1 - Scanning Trip June 2016

Yesterday we made lots of preparations for the experiments we were going to run. I got the fun task of having to separate chia seeds from the mucilage that they release when they are mixed with water. To do this the chia seeds had to be soaked in water for four hours. Then I poured them into a large syringe. I emptied the syringe against a sieve to separate the seeds from the mucilage. The mucilage is strongly bound to the seeds so I had to apply a lot of force to get the mucilage to go through the sieve. If I didn't press hard enough the seeds and mucilage squirted out of the side of the syringe. One time when this happened I ended up with quite a lot of chia seeds stuck to the wall!

Here is a picture of the syringe and the sieve I was using. Underneath the sieve there is a plastic pot to catch the mucilage.

This is a picture of the chia seed and their mucilage.

Once I had separated the seeds from the mucilage I then had to use a pair of tweezers to pick out all the bits that had managed to pass through the sieve. This was quite difficult. It was like having to pick the solid bits out of a very large bogey!

Sam, who was in charge the experiments, showed us how they should be carried out and we started the first one. This was pretty simple. Put the sample in the scanner, scan it at three different heights and then repeat with the next sample.

The Swiss Light Source

This week myself and a team of researchers from the University of Southampton have travelled to Switzerland to conduct some experiments at the Swiss Light Source (SLS). The SLS is part of the Paul Scherrer Institute (PSI). It is the large round building in the picture below:

www.psi.ch

In the center of the SLS is a particle accelerator. Electrons are made to spin around a ring, getting faster and faster. When they reach a high enough speed they are released out of the different 'beamlines' and scientists use these released electrons of conduct experiments. 

The inside of the building looks like this: 

www.psi.ch

We are using one of the beamlines called TOMCAT to x-ray fungi and roots within soil samples. We use the electrons to create a super bright light that means we can image a soil sample in a few minutes.

You can find out more about the SLS at their website:
https://www.psi.ch/sls/
and the TOMCAT beamline:
https://www.psi.ch/sls/tomcat/tomcat

How does the flytrap catch a fly?

An internet search revealed the fascinating way in which the Venus flytrap catches flies. There is a brilliant video from the BBC which explains it really well.

The inside of the leaves of the flytrap secrete a sweet nectar to attract insects. They also have a few trigger hairs. When the fly comes along to drink the tasty nectar it touches the trigger hairs. The trap won't shut if the fly only touches one of the hairs, the trap doesn't want to react to a false alarm, but if the fly touches two of the hairs, one after the other within a certain period of time, the trap snaps shut. The hairs that grow around the edges of the flytrap leaves are called cilia and these interlock together forming prison bars to stop the fly escaping.

After reading this, I was curious to know what killed the fly. Was it suffocated by the plant and then eaten? Or did the digestive juices get to it first - was it eaten alive?

http://www.livescience.com/15910-venus-flytrap-carnivorous.html
http://phys.org/news/2007-04-easy-oxygen-bug-life-full.html

How often should we scan the flytrap?

To find out how often we should scan the flytrap we needed to know how long it took for it to digest a fly. A quick internet search found many helpful websites about Venus flytraps. I have put a few links at the bottom of this post.

A flytrap digests a fly in 5-12 days. This gives us a range but we don't know exactly how long it will take in our case. We decided to scan the flytrap every 3 days after it trapped the fly until the trap opened again. If the flytrap digested the fly quickly, e.g. in 5 days, this means we would have a scan half way through the digestion process.

http://www.livescience.com/15910-venus-flytrap-carnivorous.html
https://www.flytrapcare.com/
http://www.bbc.co.uk/nature/life/Venus_Flytrap
http://science.howstuffworks.com/life/botany/venus-flytrap4.htm