This week in triple science we continued to learn about monoclonal antibodies. We began by learning about vaccinations, we learnt that vaccinations give us weakened/inactivated pathogens so our immune system can make the antibodies needed to fight them off in the future. Some of our white blood cells then become memory cells that remember how to make the specific antibodies for that pathogen.
We also found out that monoclonal antibodies are used in pregnancy tests. On a pregnancy test the monoclonal antibodies have a dye attached to them and they bind to HCG so when the person’s urine is in that area it detects if they have HCG or not. If they do, the monoclonal antibodies are trapped in an area further along the pregnancy test which makes that area turn to the colour of the dye. If they don’t have HCG the monoclonal antibodies go straight past that area. HCG is a hormone produced by the placenta when a woman is pregnant.
In our lesson we discovered that mouse lymphocytes are combined with tumour cells to make a hybridoma cell. The tumour cell divides continuously inside and outside of the body allowing many copies to be made and the mouse lymphocytes make the antibodies needed.
Our next lesson was on Wednesday and we learnt how monoclonal antibodies are used for cancer treatment. We learnt that monoclonal antibodies are used for:
• Blocking receptors on cells to prevent pathogens from binding.
• Binding to a pathogen and triggering an immune response.
• Drug delivery.
One advantage of using monoclonal antibodies is that they only bind to specific diseased or damaged cells, this way the other cells in that area won’t be harmed like they are in other treatments such as radiotherapy. A disadvantage would be that they initially created more side effects than expected, the monoclonal antibodies produced were mouse antibodies which triggered an immune response in humans.
In our last lesson of the week we learnt about growing bacteria in a lab. We now know that bacteria divide by binary fission. We also know that after a certain amount of time the bacteria would be forced to stop growing as there wouldn’t be sufficient nutrients to support all of them. We did a practical in that lesson where we grew our own bacteria. We were given agar plates which had been sterilised in an autoclave before we received them. We then had a Bunsen burner so that the heat would kill any bacteria in our working area. We had to put our inoculating loop inside the flame of the Bunsen burner in order to sterilise it. We then spread some E.coli it on the agar and sealed it with Sellotape to make it airtight and prevent cross contamination.
Exam questions that I think might come up on this topic:
1. Why do the agar plates have to be put in the autoclave before being used for experiments?
A. The agar plates are sterilised so there is no chance of cross contamination.
2. What is an antibody?
A. An antibody is a protein produced by white blood cells which bind to pathogens to kill it.
3. What is a monoclonal antibody?
A. Monoclonal antibodies are proteins produced from a single clone of cells.
4. What is a pathogen?
A. Pathogens are harmful bacteria.
5. What is a clone?
A. A clone is an organism that is genetically identical to another organism.