Automated Colony Counter

Overview

An automated colony counter does in two seconds what a microbiologist used to do by hand with a marker pen and a tally counter: count the bacterial or fungal colonies grown on a culture plate. Colony counts underlie a huge amount of routine lab work, testing water and food for contamination, measuring how well a disinfectant works, titering a bacterial stock. Counting hundreds of dots by eye is slow, tiring, and inconsistent between people, so the instrument photographs the plate and lets software do the counting under fixed, repeatable lighting.

The result is not just a number but an annotated image, with every colony the software counted marked on screen, so the operator can confirm the count or nudge it where colonies merged or the agar was cloudy.

How it works

A culture plate is set on the Dish Stage, a recessed platform with a contrast background and adapters that center any dish size in the same spot every time, consistent placement is what makes repeat counts comparable. Above it, the Illumination Dome floods the plate with even light. Lighting is the quiet heart of the instrument: faint or translucent colonies only stand out under shadow-free illumination, so white LED rings light the dome for reflected views while a backlight panel can light the dish from beneath for transmitted-light counting.

The Imaging Camera looks straight down through a fixed lens, capturing the whole plate sharp and in frame. Its frames go to the Image-Processing Board, a vision SoC that segments the image, separates colonies that touch, and applies size, shape, and color gates so debris and bubbles are not miscounted as growth. Out comes a count and an overlay marking each detected colony.

That overlay appears on the Touchscreen Display, where the operator confirms or corrects it before exporting the result. The whole stage sits inside the Housing, whose Light Shroud blocks room light so every plate is imaged under the same controlled conditions rather than whatever the bench lighting happens to be.