November 30, 2023, 07:32:32 PM
Forum Rules: Read This Before Posting

0 Members and 1 Guest are viewing this topic.

retrojohnnycanuck

• New Member
• Posts: 3
• Mole Snacks: +0/-0
Calculation Question For Adding Mucin to Broth
« on: February 12, 2021, 02:58:52 AM »
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?

Babcock_Hall

• Chemist
• Sr. Member
• Posts: 5494
• Mole Snacks: +311/-22
Re: Calculation Question For Adding Mucin to Broth
« Reply #1 on: February 12, 2021, 09:26:26 AM »
I am not sure how you decided on 14 µg.  Can you show that calculation?

retrojohnnycanuck

• New Member
• Posts: 3
• Mole Snacks: +0/-0
Re: Calculation Question For Adding Mucin to Broth
« Reply #2 on: February 12, 2021, 09:36:27 AM »
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).

Babcock_Hall

• Chemist
• Sr. Member
• Posts: 5494
• Mole Snacks: +311/-22
Re: Calculation Question For Adding Mucin to Broth
« Reply #3 on: February 12, 2021, 10:42:34 AM »
Can you show your attempt to calculate the volume of mucin needed?

retrojohnnycanuck

• New Member
• Posts: 3
• Mole Snacks: +0/-0
Re: Calculation Question For Adding Mucin to Broth
« Reply #4 on: February 13, 2021, 07:31:17 AM »
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

Babcock_Hall

• Chemist
• Sr. Member
• Posts: 5494
• Mole Snacks: +311/-22
Re: Calculation Question For Adding Mucin to Broth
« Reply #5 on: February 13, 2021, 09:16:57 AM »
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.