Life Sciences lab classes explained

Last week you set up some PCR reactions.... if you are a bit puzzled about what that was all about, read on! PCR   stands for   P olymerase   C hain  R eaction. This is a really neat technique that allows you to amplify up (or in other words, make a lot of) a particular gene that you are interested in. Here is a youtube video I found about PCR...... it is quite a long video, but it actually explains the principle of PCR really well !! Last Tuesday you set up PCR reactions to investigate a gene (called  SBE1 ) that has two possible forms - in its ' r '  form, it results in   wrinkled   peas, and in its ' R ' form, it produces  round   peas. Last week you set up three PCR reactions and these have been put into the thermal cycling machine for you. Here is a reminder of what was in each tube: One of the tubes was the control - instead of adding any DNA you added water, so there should be no amplified DNA in this tube O...

You are now on the verge of your last practical this term!  image taken from: http://en.wikipedia.org/wiki/Pea ! This practical is connected to practical 9 ! In your last practical you isolated DNA (from peas), and analysed the purity of the DNA using spectroscopy.  You also set up  PCR reactions designed to amplify a specific region of a gene from DNA extracted from both round peas and wrinkled peas .  In practical 10   you will be analysing the results of your PCR reactions using agarose gel electrophoresis. Here is a step-by-step day plan: ACTIVITY 1 :  Use agarose gel electrophoresis to separate and visualise the PCR products from the PCR reactions you set up during activity 3 on day 1 ACTIVITY 2 :  Practice analysis of agarose gels with DNA separated on them - using pictures in your manual  ACTIVITY 3 :  Analyse the results from your own agarose gels (i.e. you are looking at t...

On Tuesday you will be using the centrifuge for the first time.  There are some very specific things you need to know about using a centrifuge, so here is a quick video showing you how.... plus, using a centrifuge is in your competency training, so this video will help you with that!  :)

Can you believe how time has flown - you are now on the verge of your last two practicals this term!  image taken from: http://en.wikipedia.org/wiki/Pea ! The next two practical are connected ! - some of what you do in the first practical will give you results in the next practical Your last practicals will be all about isolating DNA (from peas), and analysing DNA.  In the first week   you will be isolating DNA from peas and then assessing the purity of the DNA you have isolated, and the concentration of the DNA. You will also be setting up PCR reactions designed to amplify a specific region of a gene from DNA extracted from both round peas and wrinkled peas. In the second week   you will be analysing the results of your PCR reactions using agarose gel electrophoresis. Here is a step-by-step day plan to day 1: DAY 1  (Tuesday of week 10) ACTIVITY 1 :  Isolate DNA from peas. You should watch the video on VITAL about spool...

I have noticed that some of you have some funky ways to round your numbers!!  Heads up guys, we don't expect anything fancy, just round up if you have a 5 or above to the right of the digit you are rounding, or do nothing if you have a 4 or below to the right of the digit you are rounding.... image taken from: https://www.tes.com/lessons/NMCs-ufl5zyH1Q/rounding So some examples.... 1.6 rounded to 1 significant figure would be 2 2.8893 rounded to 4 significant figures would be 2.889 3909 rounded to 3 significant figures would be 3910 4599 rounded to 3 significant figures would be 4600 I have checked with your lecturers - this is the way they want you to do rounding! So, nothing special :)

This video walks you through how to carry out a serial dilution in the lab.  Serial dilutions will be coming up tomorrow, and again in later practicals  (plus serial dilutions are a part of your competency testing!),  so it is important for you to understand what is going on, and how to carry out a serial dilution. This video has demonstrated a series of 10 x dilutions.  You could have done a series of any kind of dilution (i.e. 2 x, 3 x, 4 x etc).  For different dilution series the volumes you use may change, but the basic principles of how to perform the serial dilution will be the same. I hope that helps you out

You will be making some  serial dilutions   on Tuesday - I have noticed that these tend to puzzle some of you! A   serial dilution  is a  dilution performed several times in a row ,  so that you end up with a set of solutions, where each solution is less concentrated than the previous solution.... perhaps this sounds cryptic, so here is what I mean in a diagram: So, in the diagram above there is a set of solutions, and each solution is 10 x more dilute than the previous solution. This would be the result of a   serial dilution .  So how was this serial dilution performed in order to get this set of solutions? Well, some of the 100 M solution would have been pipetted into a new container and then diluted 10 x to make the 10 M solution. Then, some of the 10 M solution would have been  pipetted into a new container  and then diluted 10 x to make the 1 M solution and so on... In this example, seeing as it is a 10 x di...

In practical 8 you will be practising preparing a protein solution, making a standard curve and looking at how absorption spectra change between oxidised and reduced haemoglobin...  During this lab you will be: practising concentration calculations making up a protein solution of known concentration performing a serial dilution of your protein solution using your set of diluted protein solutions and a spectrophotometer to create a standard curve using your standard curve to find the concentration of a protein solution of unknown concentration  Using the spectrophotometer to look at how the absorbance properties of oxidised and reduced haemoglobin differ The day will be divided into the following activities: Activity 1 :  You will prepare a protein solution of known concentration, and then from this you will perform some serial dilutions of your protein solution so you have a set of protein solutions of decreasing protein concentration. You ...

A lot of you seemed to struggle with the Red Blood Cell calculations in practical 7...let me try to clarify things a bit for you. First of all, you had to calculate the volume of one large square on the haemocytometer: So, when we say one large square, we mean the square I have highlighted with green.  You know from the diagram in your notes that the sides of the square are 1 mm long, and if you read the information about the haemocytometer, you will know that the depth of this square is 0.1 mm. So, to calculate the volume of this square you have to do: 1 mm x 1 mm x 0.1 mm =  0.1   mm 3   Questions 2a, b, c and d  want you to covert  0.1   mm 3  to other units.  The one I want to focus on is expressing  0.1   mm 3  in  μ l.   This is actually very simple, you just need to know that:                                   ...

Here are some lovely results from today :)

So, following on from my previous post, what would happen if you added a sugar solution to your 3D array of red blood cells bound together by lectins?  Well, one of two things might happen.  Either,  the structure of the sugar in solution is so different from the sugar on the red blood cell surface to which the lectin is bound that nothing will happen......  Or,  if the structure of the sugar in solution is similar to the sugar to which the lectin has bound on the red blood cell surface, the sugar will compete for the binding site of the lectin proteins. In this case, the more complementary the sugar in solution is to the lectin, the lower the concentration the sugar will need to be to disrupt the binding of the lectins to the red blood cells. In any case, once the binding of the lectins to the red blood cells is disrupted, the 3D array will be lost. Simple really!