Dear All,
In experiment to treat cell culture with different substances in different point of time, for example the cell was treated with 10ul of solution A first for final concentration (f.conc) =100uM (total volume 2ml), then after 2hr, treating the cells with 10ul of solution B for f.conc =200uM (total volume 2.01ml). The f.conc of solution A will be slightly diluted. If there are more solution C, D, the solutionA will even become more diluted.
My point is that the final concentration would not be exact as written in paper. Is this ok? Does it have a acceptable deviation range of f.conc? And Is there a method to make all treating solution final concentration as close as the proposed one as possible?
Thank you
When you culture the cell the medium will concentrate with time so the final concentration will increase. In general, as long as the concentration is not off by 10-15% will be acceptable judging from all scientific experiments will have 10-15% variation. Do the best if you can.
Acceptable concentration of a compound while treating cells in culture depends on a number of factors (variables), including cells in question, vehicle con. in which a compound was dissolved, and the stability of the compound when incubated at 37 degree C. Therefore, in the absence of specific information, the response by Ru-Jeng may be ok to proceed. However, the outcome of the experiment would become un-interpretable and it would be harder for any one to reproduce the experiment.
I agree with Divaker's opinion completely. But in reality the volume of the medium will decrease with time even we humidify the incubator. If you do the experiment yourself, as I do everyday, then you will find out a 6 ml medium you put in by 24 hours it can go down to 5.5 ml very easily. Another thing most people will assume is the compound will be stable which is mostly not true. Perfect scenario will be measuring the amount of the medium every time when you add another compound but you can easily end up with contamination. It is just like one old professor criticize my western blot was not a straight line whereas his is always straight. But when I asked his lab tech to learn the trick they told me the professor has never done any western blot in his life and the tech only show him the cropped picture which is always straight. Also, you need to think about in real biologic body the effective concentration is within a range and not a fixed concentration. Yes, if it is 10 times off then it should be avoided.
Our goal is to increase reproducibility in research. Therefore, an actual documentation of the methodology is highly desirable to increase reproducibility in any field.
Totally agree that reproducibility is the key in scientific research. But how precise our measurements should be? Will 5% off too much?
- Badges
- Science method