November 1, 2017 (Vol. 37, No. 19)
Strong Points: Ability to manually correct/modify counting algorithm
Weak Points: Colony identification algorithm not perfect; limited free trial
Free 7-day trial (in-app purchase to full version for $0.99)
The Colony-Forming Units (CFU) Scope app has the potential to save researchers the tedium of comprehensively counting bacterial colonies on plates, though investigators may have differing degrees of success with the app depending on the contrast of the microorganism that they are trying to count relative to the plate background. Researchers can use the app to count colonies from pre-existing photos on the mobile device, or they can take a photo of their plate from within the app itself. Based on the user-specified minimum colony size, the app algorithm draws circles (or squares) around all of the perceived colonies and displays the total number of areas that had been drawn as the “count” for that plate. The app user can manually tweak the output of the calculation (as the algorithm is far from perfect) by using the “plus” and “minus” buttons to add or subtract areas on the image. The total count is automatically updated as users do this.