THE PROBLEM
Your plate count does not match the dose you planned
You set the dose from OD or McFarland. The plate count arrives one to seven days later, and it is off. Often, you have to repeat the experiment.
WHERE THE DOSE MUST BE RIGHT
THE SOLUTION
Count the cells before you dose
1Dilute your stock
Into the measuring range
2Measure
About two minutes, no calibration curve
3Calculate
The dilution to your target dose
4Dose
At the concentration you planned
NO CALIBRATION
McFarland 0.5 ≈ 1.5 × 108 is an E. coli number
Your organism has its own conversion factor, and it shifts as the culture grows. BactoBox counts the cells, so there is no factor to build. It works from the first sample, also for organisms nobody has calibrated.
All three at McFarland 0.5
Illustration. Turbidity tracks cell mass, not cell number. Bigger cells mean fewer cells per mL.
WHY IT WORKS
Dose viable bacteria, counted in two minutes
In an active culture, every cell BactoBox® counts also forms a colony. So the number you dose is the number of viable bacteria.
PROOF
Peer-reviewed studies that already set their dose with BactoBox
Nature Communications 2025
MiceCounted L. reuteri to set the oral dose in germ-free mice, in a study of the gut and behaviour.
Park et al., POSTECH, South Korea
PNAS 2026
Insect larvaeSet the S. aureus inoculum for Galleria mellonella killing assays.
Mattingly et al., Emory University, United States
Gastroenterology 2025
Human cellsCounted F. prausnitzii to standardise the dose for stimulating human monocytes.
Danne et al., Sorbonne Université, France
GOOD TO KNOW
Frozen, dried or stored stock
Holds cells that no longer form colonies, so the count and CFU differ. Grow an active culture first.
Organisms that clump
Get in touch, and we will look at your organism with you.