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  • Appropriate units for specimen types – molecular (eg. DNA/RNA)

    Posting on behalf of @Peter_MacIsaac:

    One of our tissue banks has requested an internal change to OS default units for the molecular class of specimen types (eg. DNA/RNA) from micrograms ug to nanograms ng.
    Seeking input from other institutions about how you manage units for this type of micro specimen/aliquot

    The issue is that OS allows only a single default unit for each of the 4 major specimen type classes for mass and concentration. If we change then we have to identify all previous specimens stored and adjust their units (in this case multiply by 1000) as changing the units does not change the quantity. As it happens this is not a major issue as we have very few stored specimens of this type and easy to change.

    When I ran a query on specimens for DNA/RNA the few we had came up with mass around 10ug – so to change to nanogram would mean recording as 10,000 nanogram? too many zeros for usability and reliable data entry?

    However as this change impacts any future users of this type of specimen, would appreciate a crowd sourced view of how this is done elsewhere – ie. do you use micrograms or nanograms
    What is the common practice in describing the mass/concentrations of this type of tissue sample.

    Dr. Peter MacIsaac
    Clinical Research Informatics – Open Specimen Coordinator
    Hunter Medical Research Institute
    Newcastle Australia.

    I have encountered this issue as well and am looking for a solution. We have teams that differ on what units to use for which SP types and it currently looks like you can only have one unit defined per SP type.

    My initial work around was to ask teams to create a custom field to record their specific units if the default wasn’t want they wanted, but it’s not the ideal solution. It’s confusing for data entry users, and custom fields are not always compatible with some of the other features (generating auto-labels for instance).

    Are there any plans to allow the user to define what unit they want per SP type upon data entry? Or maybe that could be set up at the CP level?

    Thanks in advance,

    Sam Walkow
    BC Children’s Hospital
    Vancouver, Canada


    I would like to change default units for some specimens. E.g. DNA from ug to ng: volume ug to ul and cocentration from ug/ml to ng/ul.I found this chat from 2017 and I am wondering if there is any update on how to solve this.

    Thank you.
    Best wishes,

    Hi @Andreia_Silva,

    You can change the quantity and concentration units using the dropdown manager. If there are no properties added for DNA, you will have to add these.

    Please refer to the properties section on the Wiki page https://openspecimen.atlassian.net/wiki/x/bYDEAw for more details.


    Thank you Neha.

    I’ve tried that as seen on the screenshot below:


    … but the DNA still have the old units:

    Many thanks,

    Hi @Andreia_Silva,

    Can you try refreshing the page once, after changing the units?
    I was able to see the changed units on adding the properties you have mentioned.