When we speak about co-localisation in optical microscopy, it is commonly admitted that two proteins are found at the same location, which implies that they are seen on overlapping pixels in two colour channels when using the most appropriate sampling rate and magnification for image acquisition. However, two observers might not draw the same conclusions from this coincidental event. Cell biologist would conclude that two proteins co-localise while physicist would rather say that under current conditions, it can not be excluded that the two proteins are at the same location!
These simplistic interpretations are already a first step of controversy. The situation is even more complicate when the localisation pattern of two proteins is mixed. At this situation, there are two possibilities : 1-Colocalisation, the objects are totally or partially colocalized, 2-Proximity, there is no overlapping pixel but the objects are close and we may need to calculate the distance between them for understanding their interaction.
In our approach, we guide the user to obtain segmented images to quantify his data. We created a macro that provides different possibilities for spatial analysis, object colocalisation, distances between the two populations of object and statistics on each object. Besides result tables, we introduce an ROI selector to navigate through images and the possibility to save them. We create a new tool to perform these processes in a plugin to the public domain ImageJ software (Rasband, W.S., 1997-2015), which is named DiAna Distance Analysis)