I want to calculate the CFU/mL concentration for the cell growth by using the OD600 nm in M. smegmatis. Kindly tell me what are the possible solutions.
UV at OD600 nm will absorbs the entire dispersion including the dead cells and the equivalent suspension. I think the best for you is to develop your own standard curve for your strain. You prepare a inoculum, plate it and count the number of colonies CFU/ml and in parallel prepare different concentrations of the inoculum in broth and measure at 600nm and draw your curve (OD vs number of bacteria). You can derive the number of bacteria CFU/ml in different concentrations from the inoculum concentration (plated and counted). You may use McFarland standard for measuring the cells in inoculum, but plating method to fix the inoculum is best for your purpose of counting the bacteria at 600 nm
I agree with Srinivasan Krishnamoorthy . To add to the above, you can serially dilute the culture and plate different dilutions on the plate. Measure the absorbance for all the dilutions that you plated. That will help you to determine the CFU/ml more accurately. Plate at least 4 - 5 dilutions.
You can also refer this article: Article Measuring of Mycobacterium tuberculosis growth. A correlatio...
Thank you very much Pragun Muthya , Srinivasan Krishnamoorthy and Abhijeet Singh for these useful information !
- Badges
- Science topic
- Similar topics
- Biological Science
- Biota
- Eukaryota
- Fungi