Calculate %tail DNA in Fluorescent comets




I have recently downloaded CellProlifer and have run a bunch of comet images, stained by Sybr green and imaged @10X. I would really appreciate if you could suggest me how should I use the Comet tail.csv data to calculate the %tailDNA of the comets. I am attaching the cometTail.csv file and the programme file for the same.
CometTail.csv (670.0 KB)
fn120tt cell profiler all images.cpproj (813.2 KB)


@mbray Could you please help me with this :slight_smile:


It seems to me like %tailDNA would likely be calculated by the total intensity of the tail (that’d be the Intensity_IntegratedIntensity metric) divided by the total intensity of the whole comet (same column on your ‘Comet’ spreadsheet), but that is just a guess. You should consult some reviews or protocols in your field to find how that’s usually calculated.


Thank u so much for a quick reply. I will try it out and keep u posted :slight_smile: :+1:


Sure thing - here is an article specifically validating CellProfiler for comet tails: In addition, there are a number of forum posts if you search ‘comet’ that might solve particular issues.

Have fun!


Hi @Anne_Carpenter,
Thank you for the suggestions, but the pipelines for Silver Stained comets and fluorescent stained comets are different. In the prior one, there is a direct output value for %tail DNA whereas in the later, its otherwise. Fluorescent comets have indirect values that can be correlated as %tail DNA but journal reviewers would expect direct values.

I am not good at programming, so am unaware of a way to create a Calculate module that can do the job.

Thank you anyways :slight_smile:


Hi @bcimini,

the Intensity_IntegratedIntensity values are exactly the same for whole as well as tail comets. Which is why the division value is 1. Am I doing something wrong?


Hmm, that sounds like your segmentation isn’t working correctly then. Have you verified/troubleshot the images to make sure they look right?