A free browser tool that checks dynamic light scattering (DLS) data and, if you add TEM images, compares the two. It looks for problems in four stages (interpretation, measurement setup, sample preparation, synthesis or flow) and tells you what each finding means and what to fix.
Researchers and students who measure particle size with DLS and TEM: polymer, lipid, metal and inorganic nanoparticles, and coated particles.
Yes, it is free during the public beta. Before any paid plans start, we will announce them; nothing is charged without your explicit purchase.
Wali Inam, Turku, Finland.
No. Your measurement files and TEM images are analysed only in your browser and are never uploaded. Only what you choose to send in the review or bug-report forms is sent to us.
Your email address if you sign up, and anonymous usage counts (for example how many analyses were run). See the privacy policy for details.
Yes, from the account menu ("Delete my account"). It removes your account and email address.
DLS: Malvern Zetasizer .dts files and CSV exports. TEM: image files (TIFF, PNG or JPG).
Visitors without an account can run 10 full checks per month. Signed-in users have no limit during the beta.
It is free, there is no password (we email you a sign-in link), and signed-in users are not limited.
The accepted difference between DLS and TEM sizes: polymer ±15%, uncoated metal or inorganic ±5%, coated particles ±10% (plus the expected coating), other or unknown ±10%.
Pick "Coated particle", then the core and the coating. DLS measures the hydrodynamic size, so it should read about the TEM size plus two coating thicknesses. The tool compares your data with the thickness range for that coating and shows the core and shell. If your coating is not listed, write its name and enter the thickness if you know it.
The number-weighted DLS size is compared with the TEM mean and coloured: agreement, minor, medium, major or smaller. A medium or major gap points first to sample preparation, and if that is clean, to the synthesis.
DLS weights large particles very strongly. From your TEM sizes, the tool calculates the Z-average a perfectly dispersed sample would give and compares it with the one you measured. A much higher measured value points to larger species, such as aggregates, in suspension.
Dust and aggregates are the most common and cheapest causes, so they are ruled out before the synthesis is blamed.
It applies checks and thresholds taken from the published literature. Every finding lists its source; thresholds labelled "standard practice" are guidance, not standards.
They are estimates, not certified measurements. They do not replace expert judgement, validated methods or regulatory testing. See the disclaimer.
No.
When a result suggests mixing problems, the report shows a Flow & mixing card with a button to contact us about a fluid flow analysis. The button only opens a contact page; no data is sent.
Use "Report a problem" at the bottom of the tool page: say what happened and add a screenshot if it helps.
Yes, at the bottom of the tool page. Reviews are shown publicly only if you tick the box and after we have checked them.