Serial Dilution Lab Report
Huge Micro Problem As you know, bacteria are everywhere, invisible to the naked eye, yet influencing every environment on Earth. What happens when you need to know how many individual bacterial cells are contaminating a food, living in an environmental sample, or growing in a culture tube? You need some method for counting the bacteria accurately. But, it is not uncommon for a liquid culture of bacteria to have a billion cells in every milliliter of media.
What are antibody tests? Antibody tests involve analysing a patient’s sample (usually blood) for the presence or absence of a particular antibody (qualitative). Serial Dilution - Download as Word Doc (.doc /.docx), PDF File (.pdf), Text File (.txt) or read online. Label sterile test tubes with dilutions. Dilutions are usually 10-fold steps: 1/10, 1/100, 1/1000, 1/10000, etc. Test tubes should already have sterile water (or sterile saline) in them. Example of Serial Dilution for Lab Report We tested the number of bacteria in the eighteen hour old S. Typhimurium broth culture with a serial.
Think about that for one second. In your kitchen, you probably have a teaspoon. Every teaspoon has about 5 milliliters. That means that every teaspoon of liquid could potentially have 5 billion bacteria in it. Even if you counted one bacteria every second, it would take you over 150 years to get to 5 billion!
Obviously, this is not a viable option. Powertracks Pro Crack: Full Version Free Software Download. So, what can you do? You need fewer bacteria to count.
Ideally, you want to only have to count between 30 and 300 bacteria, a range of numbers that takes only at most a few minutes to count. But, how do we get there? Serial Dilution The answer is through dilution. If you simply pull out a smaller, exact quantity of culture liquid, you could count those bacteria and, based on how much you pulled out of the total, you can determine how many bacteria are in your original sample.
Tractor Ted Dvd Download. Sounds easy, right? But first, one more analogy: you have billions of bacterial cells and need to get down to 30 to 300.
In order to do that, you would have to dilute your sample about 10 million-fold. To do this, you would need to take about 15 milliliters of your sample, about 3 teaspoons, and dilute it into your swimming pool!
I doubt this is a viable option, especially if you're working in a cramped lab space. So instead, let's not dilute just once. We can dilute once, then dilute this dilution, only to dilute this dilution, and so on until we get to the appropriate concentration of cells. This is called a serial dilution. A serial dilution is a series of sequential dilutions used to reduce a dense culture of cells to a more usable concentration. Each dilution will reduce the concentration of bacteria by a specific amount. So, by calculating the total dilution over the entire series, it is possible to know how many bacteria you started with.