Hello peers,
Does anyone have experience with particle size analysis (dynamic light scattering) with lentivirus? I would really appreciate if you can suggest me some papers or resources. Thank you!
She.
Hello there,
the sample preparation is probably your main concern? You could try google scholar as a starting point https://scholar.google.com/scholar?hl=de&as_sdt=0%2C5&q=DLS+and+lentivirus&btnG=
Hello Ulf Nobbmann , thank you for your response. I have tried measuring without any actual sample prep, i.e undiluted lentivirus and it seems to be displaying as a multimodal sample. yes, sample preparation. Thank you, I will try. If you come across anything, please share! Thank you again for your response.
Hi She S. , when measuring undiluted you may want to check for the quality of your data, since DLS typically works best at relatively low concentrations. A good check is to go for a dilution series with sequential dilution. If your distribution stays multimodal at all dilution steps then you know it is not an artifact from too much particles in the scattering volume. Some variants of DLS such as SR-DLS tackle this directly allowing almost always undiluted measurements, but if you are using a regular basic DLS for a static sample of viruses I would definitely just make some dilution series to make sure.
As a word of caution, if this is your first time using DLS, make sure you input the correct medium viscosity in you system of choice, because you are working with Einstein-Stokes any error in your viscosity will result in a direct error of your particle size calculation.
Hi Albert Grau-Carbonell , thank you for your reply. I appreciate it! I have attached an image of my readings ( I measured 1 undiluted sample & read it 3x). Also, unfortunately, i do not have the medium viscosity value at the moment to account for viscosity. I will have to find that. Doesn't dilution increase aggregation?
Hi She S. , two things:
- The two peaks of your data are very far away, almost a factor 10x between them, so they are probably both real. However it could also be that you have a continuous distribution (one very wide peak) and the algorithms is finding that two peaks at this sizes gives a good approximation of the overall correlation function of the measurement.
- Dilution will only increase aggregation of that implies a change in solvent to a solvent in which you particles are not stable or if the stability of your particles depends on something diluted in the solvent at a minimal concentration (for example polymers for steric stabilization). If you are diluting in its native solvent it should be fine!
Hello Albert Grau-Carbonell
Thank you for your reply! So, i tried to re-run this undiluted sample just to see if i was getting the same results and i did it over an hour. I measured (the same sample) after every few minutes to see if there is a trend in this separation, but truthfully i did not observe a trend as the peaks were all over the place, i.e for some readings it was a broad peak and other readings gave me 2 or 3 peaks. Would could be the reason for this? (Note: i measured this 1 sample without taking it out of the cuvette holder in the DLS instrument).
I plan to dilute the sample in PBS as we do not have the formulation buffer of the sample. This article mentions about diluting 1:100 in PBS "Physical Characterization and Stabilization of a Lentiviral Vector Against Adsorption and Freeze-Thaw".
Thank you again!
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