Assume that you measure the OD of two Ecoli cultures culture

Assume that you measure the OD of two E.coli cultures: culture A and culture B. The spectrophotometer gives you a reading of 3.1 for culture A and 0.03 for culture B. What would you do to determine the concentration of culture A and B and why? Give a detailed explanation!

Solution

Ecological shows maximum absorbance at OD 600, in the first culture A, the OD value is 3.1 which shows high density, always it would not exceed 1.0 so we need to dilute the sample for calculating the concentration.

The culture B OD is too low about 0.03 , so the dilution factor is multiplied to determine the concentration I.e.Cells/mol.

1. CFU/ml is calculated = no of colonies / volume of sample plated x dilution factor .

2. A= molar extinctions x concentration x pathlength. Also used.

Only wd Of values it\'s not enough to find the concentration.