How the Coulter impedance and optical principles actually count cells, why the aperture must be larger than the cell, how trypan blue separates live from dead, and when a cell coun...
Serial dilution is the standard method for estimating bacterial counts in samples. Learn the 10-fold dilution procedure, CFU/mL calculation, the 30–300 colony rule, common errors (...
How ATP hygiene testing uses the luciferin-luciferase bioluminescence reaction to measure surface cleanliness in seconds, what RLU readings really mean (total organic residue, not...
How manual, digital, and automated colony counters work, how they connect to CFU/mL counts and the 30–300 rule, and how to choose the right one for your lab.
Membrane filtration concentrates bacteria from large water volumes onto a 0.45 µm filter for direct colony counting. Learn the principle, step-by-step procedure, mEndo vs mFC agar...
The spread plate technique distributes a diluted sample evenly across pre-dried agar to produce surface colonies for counting and isolation. Learn the procedure, CFU/mL calculation...
The MPN test estimates bacterial concentration using statistical probability across serial dilution tube patterns. Learn its three-step procedure (presumptive, confirmatory, comple...
The pour plate method mixes the bacterial inoculum with molten agar before solidification, producing colonies both within and on the surface. Learn the procedure, 30–300 count rule...
The streak plate method isolates bacteria into pure cultures by progressive dilution across an agar surface. Learn quadrant, T-streak, radiant, and continuous methods, common error...
How bacteria are isolated as pure colonies and enumerated as CFU/mL, and why both steps matter for diagnosing infection, food safety, and water testing.
