Chemical Forums
Specialty Chemistry Forums => Biochemistry and Chemical Biology Forum => Topic started by: retrojohnnycanuck on February 12, 2021, 02:58:52 AM
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I am currently trying to culture a bacteria species called Akkermansia spp. The recommended method is to add 100 μL of the bacteria stock (in solution form) to a tube of Brain Heart Infusion broth containing mucin.
Firstly, I need to dissolve the mucin powder in 1M NaOH to make it soluble. It should be done at 20 mg (i.e. 0.02 g) of mucin powder to 1 mL of 1M NaOH.
Secondly, I need to add 2 μg/mL of the dissolved mucin to a tube containing 9 mL of Brain Heart Infusion broth. That means I need to add 14 μg of the dissolved mucin.
Problem: How much of the dissolved mucin (in μL) should I add to my tube of Brain Heart Infusion broth?
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I am not sure how you decided on 14 µg. Can you show that calculation?
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I am not sure how you decided on 14 µg. Can you show that calculation?
Sorry, had a typo there. It should be 18 µg (i.e. 2 x 9).
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Can you show your attempt to calculate the volume of mucin needed?
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Can you show your attempt to calculate the volume of mucin needed?
Yes. I set up the following equation:
[(20x)/(9+x)] = 2
20x = 18 + 2x
18x = 18
x = 1 mL
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If you took 1 mL of mucin solution with a concentration of 20 mg/mL, you would have 20 milligrams of mucin. In a final volume of 10 milliliters, the concentration would be 2 mg/mL. Offhand, I suspect that your calculation has some inconsistency in units
The final concentration (which I take to be 2 µg/mL) is quite a bit smaller than the stock concentration. That means that you will need to pipet a very small volume.