To determine the volume of protein sample to add per well in a Western blot, you need to consider the desired amount of protein to load and the concentration of the protein sample.
In your case, you have a protein concentration of 1.5 μg/μl, and the final volume of your protein sample is 200 μl. To calculate the volume of protein sample to add per well, you can follow these steps:
Determine the desired amount of protein to load per well. This will depend on the specific experiment, the expected abundance of the protein, and the sensitivity of the detection method. Commonly used amounts are between 10 μg and 30 μg per well.
Multiply the desired amount of protein to load per well by the number of wells you plan to use. Let's assume you want to load 20 μg of protein per well and you have 1 well. In this case, you would multiply 20 μg by 1 to get 20 μg.
Divide the desired amount of protein in micrograms by the protein concentration in micrograms per microliter to obtain the volume in microliters. Using the example above, you would divide 20 μg by 1.5 μg/μl to get approximately 13.33 μl.
Therefore, you should add approximately 13.33 μl of your protein sample per well if you want to load 20 μg of protein, based on the given concentration of 1.5 μg/μl and a final volume of 200 μl. Adjust the volume accordingly if you have different protein loading requirements or if you are using multiple wells.
Remember to consider any additional volumes required for loading buffers, markers, or other components of your Western blot protocol.