A Craft in the Life: Lemon and Blueberry Marshmallows

When looking for something new to make/bake I usually end up choosing something fairly quick and simple. However, there are several things I have been wanting to make for a long time which do require a little extra time, care and more unusual ingredients. I love the look, taste and texture of marshmallows, but I have never had the time or confidence to try and make my own. One recipe that caught my eye recently was a lemonade and blueberry puree inspired marshmallow. So with an entire Sunday to spare I decided to try my hand at making some homemade marshmallows!

IMG_5467

Lemon and Blueberry Marshmallows

You will need:

2 tbsps Cornflour

2 tbps Icing Sugar

1 Lemon

7oz/200g Fresh Blueberries

12oz/350g Caster Sugar

½ tsp Vanilla Flavouring/Extract

6 leaves Leaf Gelatine

2 Egg Whites

Pinch of Salt

Marshmallow! 001

Let’s get started!

  • Begin by greasing and lining a baking tray (Approximately 20cm square) with baking/grease proof paper.
  • Combine cornflour and icing sugar together in a small bowl.

Marshmallow! 002

  • Add a tbsp of this mixture to the tray and shake gently to cover all sides of the tin.

IMG_5432

  • Zest the lemon and set aside.
  • In a small saucepan, combine blueberries, 1 tbsp caster sugar and juice from half the zested lemon.

IMG_5436

  • Gently simmer over a low heat until blueberries are soft.
  • Using a hand held blender or food processor, blitz until smooth then return to the pan.
  • Stirring frequently, cook until the puree has reduced to a jammy consistency, add the vanilla and set aside.

IMG_5440

  • Place the gelatine leaves in a medium sized bowl, cover with cold water and leave for 10 minutes.

IMG_5434

  • Combine egg whites, salt and 1 tbsp caster sugar.
  • In a medium saucepan, combine the rest of the caster sugar, 150ml water and heat gently until the sugar has melted.

IMG_5438

  • Bring to the boil and continue to cook until the syrup reaches 120ºC/248ºF.
  • Remove the syrup form the heat and start whisking the eggs on a fast speed until they reach a stiff peak stage.
  • Drain the gelatine, blot dry on a tea towel and add to the syrup mixing with a rubber spatula.
  • With the beaters still on, slowly add the syrup to the egg whites.
  • Continue to beat for a further 3 minutes until the mixture has cooled, doubled in volume and is thick and glossy.

IMG_5444

  • Scoop half of the mixture into another bowl, add the lemon zest, mix well and spoon into the prepared tin spreading level.

IMG_5447

  • Add the blueberry puree to the rest of the marshmallow, mix gently then spoon on top of the lemon mixture.
  • Spread level then leave until completely cool before covering with cling film and allowing to set overnight.

IMG_5451

  • To serve, tip the remaining cornflour/icing sugar mixture onto a lined tray and spread evenly.
  • Tip the marshmallow out of the tin and using a lightly greased knife to cut it into squares, coating in cornflour/icing.

This recipe will pretty much use every bowl and spoon in your kitchen! Despite that, I found that process of marshmallow making really enjoyable and on the whole actually fairly simple. The blueberry puree smells beautiful as it cooks down to a sticky delicious jam consistency which streaks the white marshmallow a wonderful purple colour. In contrast, the lemon zest adds hidden specks of yellow throughout the white layer of marshmallow.

IMG_5460

I really love the taste of these marshmallows, they are definitely less sugary sweet than shop brought marshmallows I have eaten but I quite like that! They have a soft pillowy taste that melts on your tongue to release sweet tart blueberry flavours and tangy lemon. I can’t actually believe they turned out as well as they did – for a first attempt 🙂

A Craft in the Life…

A Year in the Life: Preparing for PCR and Antibiotic Susceptibility Testing

Monday 17th February 2014

I began Monday morning checking to see if my restriction enzyme and antibiotic susceptibility discs had arrived yet. Unfortunately neither had been delivered, so I decided to begin preparing for the next stage of Escherichia coli isolate genotyping – polymerase chain reaction (PCR). I intend to use PCR in order to investigate each isolate for the presence of Bla genes which are associated with CTX-M ESBLs. By using a selection of primers, I can amplify any of the 5 types of CTX-M Bla genes – if they are present. Then run samples through electrophoresis in order to observe which type of CTX-M gene were present and had therefore been amplified. The presence of CTX-M genes is very interesting to me as they correspond to the production of ESBLs which my work is concerned with, especially in terms of antibiotic resistance.

The first stage after isolation of Escherichia coli is alkaline lysis, in order to isolate plasmid DNA from each sample. Several solutions are required for the alkaline lysis, therefore I began by preparing each:

Solution 1 – GTE (Lysis Buffer)

  • Glucose
  • Tris-Cl
  • Ethylenediaminetetraacetic acid (EDTA)

Solution 2 – SDS/NaOH (Lysis Buffer)

  • Sodium dodecyl sulfate (SDS)
  • Sodium hydroxide (NaOH)

Solution 3 – KOAc (Neutralising solution)

  • Potassium acetate
  • Glacial acetic acid

IMG_5348Unfortunately, making so many different solutions at once resulted in the accidental death of my favourite stirrer on our magnetic hotplate (Don’t worry though, he has gone on to be become the new lab fridge magnet!)

Tuesday 18th February 2014

The next stage after plasmid isolation is transformation. Transformation is the uptake of isolated plasmid DNA resistant to an antibiotic (In my research – cefotaxime) into a recipient chromosome of a cell which is in a competent state. In order to perform this I needed to produce competent cells, which required ice cold calcium chloride (CaCl2) and a 3/4 hour culture of Escherichia coli in LB broth. I began by producing a 1M stock of CaCl2, before filtering and storing it at 4ºC. I then prepared 100ml of LB broth by combining LB broth powder with distilled water in a Duran flask and autoclaving it. I also made 300ml of separate LB broth to use as a blank when measuring the OD of the 3/4 hour culture of Escherichia coli.

IMG_5322

My antibiotic susceptibility discs had finally arrived so I then inoculated individual nutrient broths with a single colony from my collection of Escherichia coli Lincoln isolate nutrient agar slopes. As I have quite a large collection of isolates now I decided to incubate 1-45 first and then finish the collection off on Wednesday. I incubated these overnight at 37ºC. Having used all of my nutrient broths, I then prepared, decanted and autoclaved more nutrient broth into glass universals.    

IMG_5331

Wednesday 19th February 2014

I began the day by removing my incubated nutrient broths from the incubator and spread plating each onto an individual Mueller Hinton agar plate. I left each to absorb for around 10 minutes before loading the antibiotic disc plunger with my newly arrived discs (Amoxycillin, Imipenem, Ceftazidime, Piperacillin/tazobactam, Ceftriaxone, Ampicillin, Cefotaxime and Gentamicin) and applying them onto each plate. These plates were then incubated overnight at 37ºC.

IMG_5332

I then inoculated the rest of the Lincoln isolate collection (46 – .140) in individual nutrient broths, and again incubated them overnight at 37ºC. As I was running low on Mueller Hinton agar plates I also decided to prepare, autoclave and pour more plates for use tomorrow.

IMG_5335

Finally, I streak plated a nutrient agar plate with a single colony from my E1 Escherichia coli nutrient agar slope ready for inoculation into LB broth tomorrow – to create competent cells. I incubated this streak plate overnight at 37ºC.

Thursday 20th February 2014

I started today preparing competent cells!

How to produce competent cells

  • Inoculate prepared and autoclaved 100ml LB broth with a single colony from overnight Escherichia coli streak plate.

IMG_5355

  • Incubate this LB broth with agitation at 37ºC for 3 hours before checking the OD at 595nm – an appropriate OD is approximately 0.35.

IMG_5361

  • Once this is reached separate the culture into two 50ml Falcon flasks, chill on ice for 10 minutes then centrifuge at full speed for 10 minutes.
  • Remove the supernatent and add 10ml of ice cold 0.1M CaCl2.
  • Re suspend the pellet by vortexing each flask.
  • Place both flasks on ice for 10 minutes before centrifuging again at full speed for 10 minutes.
  • Remove the supernatent and add 2ml of 0.1M CaCl2.
  • Re suspend the pellet by vortexing each flask and place on ice.
  • If not ready to conduct transformation, store at 4ºC in 2ml 0.1M CaCl2.

 

 

 

 

Once finished I removed my antibiotic susceptibility Mueller Hinton agar plates from incubation and began observation of clearing. Similarly to before I used a ruler to measure the zone of clearing around each antibiotic disc to the nearest mm and recorded it in a prepared table in my lab book.

IMG_5372Escherichia coli isolate 13 – if you look really carefully you can see it smiling…

I then spread plated the second batch of inoculated nutrient broths onto Mueller Hinton agar plates, allowing them to absorb, before applying antibiotic susceptibility discs and incubating overnight at 37ºC.

Friday 21st February 2014

Friday began with a supervisor meeting from 9.30am to 1pm. Once finished, I removed the second batch of antibiotic susceptibility Mueller Hinton agar plates from incubation and finished off observation/recording zone clearing into the table from Thursday.

I then decided to produce antibiotic (Cefotaxime) MLSA plates and LB broth ready for alkaline lysis and transformation next week. I began by producing a stock solution of cefotaxime to add to both agar and broth. I combined cefotaxime powder with distilled water then filtered.

IMG_5385

To prepare the MLSA and LB broth, I combined MLSA powder and technical agar/LB broth powder with distilled water before autoclaving. In order to prevent destruction of the antibiotic I waited until both were cool enough to pour and then I added my desired amount of the prepared cefotaxime stock to each. Each was then gently mixed to combine and poured/decanted aseptically.

Next week…

Similarly to last week, this week began fairly frustratingly with no restriction enzyme or antibiotic susceptibility discs! However, this did mean that I had time to prepare solutions for alkaline lysis, as well as competent cells for transformation and future PCR. I did, of course, manage to complete antibiotic susceptibility testing of all Escherichia coli isolates within my Lincoln collection and can now compare these results to data tables. This will allow me to identify those which are resistant, intermediate and susceptible to the antibiotics I used.

The next stage of my research involves me looking specifically at those isolates which demonstrate susceptibility and resistance to cefotaxime, hence my production of MLSA and LB broth containing cefotaxime. Beginning genotypic analysis of the isolates through PCR, will involve me looking specifically for CTX-M ESBLs by amplifying Bla genes. Hopefully my NotI restriction enzyme will also turn up next week, and I can continue perfecting PFGE Escherichia coli isolate plug production and PFGE running conditions!

A Year in the Life…

A Year in the Life: My MSc Research in the 1000 Most Used Words

This seems like it is going to be easy, but I get the feeling I won’t be saying that in a few hours, when I am still here shouting at my computer and wishing that I had never decided to try this out! So enough of the easy stuff, let’s get onto the hard bit!

Right, my work… let’s begin…

E.coli

…with these very very small animal like things, which I’m afraid have no other name but Escherichia coli or E.coli! (Photo from Wikicommons)

My work focuses on looking at these very very small animals, that can be found pretty much every where in the world and that are very important to life. I am interested in looking at these as they can cause people to get sick as well as making those who are already very sick get worse and become harder to make better. Some of these very very small animals can be killed using something that can stop them growing by attacking their outer or inner cell parts. (Let’s call these things Mr. Antibiotic, so this doesn’t become too confusing to read!). However, as time has gone on many of these very very small animals have stopped being able to be killed this way.

antibiotics

Hello there Mr. Antibiotic! (Photo from ZME Science)

This can be for several reasons:

  • The very very small animals have seen Mr. Antibiotic before, but have avoided being attacked/killed (For many reasons!) and have been able to change themselves to stop being killed.
  • The very very small animals have met other very very small animals which have been able to change to stop themselves being killed by Mr. Antibiotic and have been ‘told’ how to change to stop being killed too.
  • The very very small animals have been near other very very small animals that have left little ‘notes’ on how they have changed to stop being killed. They can then pick up these ‘notes’ and now know how to change too.

I am interested in this as it means that people who are very sick because of these very very small animals can’t be made better using Mr. Antibiotic. This is really bad for people who are very very sick as there aren’t many other things that can help make them better. As time goes on this will eventually mean that we only have a few types of Mr. Antibiotic left (and one day maybe nothing…) to use when people get sick because of these very very small animals. Many people are very worried about this happening as it would mean we have no way to make sick people better if they become sick because of these very very small animals which can’t be killed.

These very very small animals can ‘see’ Mr. Antibiotic and not be killed for many reasons:

  • When people take Mr. Antibiotic, but they are sick because of other very very small animals which can’t be killed this way. This allows the very very small animals present to change themselves to stop being killed if they see Mr. Antibiotic again.
  • When people are given too little of Mr. Antibiotic to kill all the very very small animals making them sick and this allows the animals time to change themselves to stop being killed.
  • When people don’t take Mr. Antibiotic for long enough so all the very very small animals making them sick aren’t killed and this allows the animals time to change themselves to stop being killed.

These very very small animals change in many different ways to stop themselves being killed. One of the these ways is to make things which help to break down Mr. Antibiotic before they can be killed. I am interested in very very small animals which make one type of these things (Again, this is going to get very confusing if I don’t call these things Mrs. Enzyme!). I have been looking for very very small animals which make this one type of Mrs. Enzyme, in the city which I work in.

I have decided to look for them in the water which is used by the city, and then made safe before it is let back into the world again. Once I have this water I use food which the animals love and can grow on to find them. I can then make sure they are what I am looking for by putting them with a few different types of Mr. Antibiotic which I hope they know how to kill by making their one type of Mrs. Enzyme. If they can make their one type of Mrs. Enzyme the animals will live and grow near Mr. Antibiotic, if they can’t they will die.

IMG_0936

Where I collect my water and very very small animals from – River Witham, Lincoln, UK

Once I have found as many very very small animals that can make one type of Mrs. Enzyme that breaks down the few different types of Mr. Antibiotic I am then interested in finding out more/other things about them. Such as:

  • How a like they are to one another?
  • What other things can they make to make sure they live?
  • What more can we find out about what one type of Mrs. Enzyme they can make?

I then hope to repeat this work in another city which has different people from different places all over the world who bring different types of very very small animals here. This is very interesting as many people want to find out how many of these very very small animals can’t be killed and if work to stop their numbers getting bigger is helping. This work is really interesting to me as I hope to see what is the same and what is different between the very very small animals in my city and the other city. I would really like to know if very very small animals are very different in different cities, if their numbers are different and if the types of Mrs. Enzyme they make are different too.

The End…

I found it quite challenging but really interesting to write this! One thing I found particularly difficult was finding alternative words/explanations for technical terms, which I think I have become very reliant on as a scientist. Is is definitely good fun to really have to think about what all those words actually mean and if you can in fact write correctly and coherently without them. I think I did a fairly good job overall! (Even if I did have to cheat twice…).

If you feel like having a go at explaining your work follow this link!

My Weeks, using only the ten hundred most used words.

Love the way this really makes you think about how to explain your work so that everyone can understand and appreciate what you actually do within the scientific field. Definitely think I will be having a go at describing my current research work using only the thousand most commonly used words…

My Science Technician Internship

Today I will be writing using only the ten hundred most used words.

It’s not going to be easy.

I know I haven’t added a written thing in a while, this is because for one week, many of the things I did were boring. After that week I did too many things and was too busy to write a written thing. Then I had a time eating idea to use only the ten hundred most used words.

This makes writing written things take much longer.

Anyway, on to my job as a help person for students. Earlier this week I took some very, very, cold – very, very, very tiny animal-like things and grew them on -not for eating- food. Then I made them as warm as a person for a night. During this warm night, they grew lots and made lots of repeats of themselves.

I then took the…

View original post 263 more words

A Bake in the Life: Lemon and Poppy Seed Loaf

A few months back I made a twist on the original Lemon Drizzle Cake, using lemon and lime. While out for coffee over the weekend, gazing at the delicious selection of cakes, I was reminded of another variation that I was really interested to try – Lemon and Poppy Seed. I love the combination of tart lemon cake speckled with black poppy seeds topped with sweet icing, so I couldn’t wait to taste this loaf! I adapted this recipe from a favourite loaf recipe of mine – increasing the lemon zest and juice for a more intense flavour, and of course adding in poppy seeds.

IMG_5313

Lemon and Poppy Seed Loaf

You will need:

Cake:

5oz/140g Butter

5oz/140g Caster Sugar

2 Beaten Eggs

5oz/140g Self Raising Flour

4 tbps Milk

2 tbsps Poppy Seeds

Finely grated rind of 2 lemons

1 tbsp Lemon Juice

Icing:

5oz/140g Icing Sugar

3-4 tbsps Lemon Juice

Let’s get started!

  • Begin by preheating the oven to 160ºC/325ºF/Gas Mark 3.
  • Grease and line a 900g/2lb loaf tin with grease proof/ baking paper (This can be tricky due to the tin’s shape, so if you can find them I would definitely recommend loaf shaped paper cases as they are much easier to use!)

Lemon Poppy Seed Loaf 001

  • Beat together butter and sugar until light and creamy (This can be done using an electric mixer, however if your butter is room temperature it is easily done using a wooden spoon).

IMG_2231

  • Gradually add the beaten egg, beating the mixture until smooth (I usually just do this in a mug!).

IMG_2240

  • Sift in the flour, then add the grated lemon zest and juice, milk and poppy seeds.

IMG_5293

  • Fold in gently until fully combined.
  • Spoon into the lined tin and bake for around 55 minutes until light brown and a skewer inserted into the middle of the cake comes out clean.

IMG_5295

  • Allow to cool in the tin for 15 minutes before placing on a wire rack to cool completely (The cake may sink slightly at this point, but don’t worry it makes it easier to ice and it still tastes great!)

IMG_5300

  • To make the icing, combine icing sugar with lemon juice until it reaches your desired consistency – I wanted my icing to still be fairly thick therefore I used 3 tbps lemon juice (You could also make a lemon glaze by combining caster sugar with lemon juice, pricking the cake with a cocktail stick and pouring over the top while still in the tin).
  • Once your cake is completely cool you can either pour/spoon it over the top and allow it to drip down the sides. Or you can place it back into the tin to prevent it dripping down the sides.
  • Allow the icing to set before cutting into slices.

IMG_2273

I love how this cake turned out – packed full of lemon flavour, zest and poppy seeds! Apart from eating it, my favour part is cutting a slice and revealing the cake inside dotted with poppy seeds and pieces of yellow lemon zest. This recipe is really easy to follow and the only part that takes time is the low temperature slow baking – this is important though as it ensure that the cake is cooked evenly and lightly brown on top. If you prefer you can make the mixture the same way but instead spoon into muffin tins, bake for 20-25 minutes then top individually with icing. Definitely give this recipe a try! 🙂

IMG_5309

A Bake in the Life…