Apparatus, systems, and methods for preparing an output sample comprising a defined concentration of an infectious agent for downstream testing

A method of preparing an output sample of a defined concentration, comprising:

• diluting an aliquot of a source sample comprising an infectious agent by a dilution factor to yield a diluted sample;
• selecting a first threshold amount and a second threshold amount from a look-up table, wherein the first threshold amount and the second threshold amount represent changes in a solution characteristic of the diluted sample;
• exposing one or more sensors to the diluted sample, wherein at least a part of each of the one or more sensors is in fluid communication with the diluted sample when exposed to the diluted sample;
• incubating the diluted sample at an incubation temperature, wherein the diluted sample is incubated when the one or more sensors are exposed to the diluted sample;
• monitoring a change in the solution characteristic of the diluted sample using a parameter analyzer or a computing device coupled to the one or more sensors;
• obtaining a first threshold time corresponding to an amount of time elapsed for the solution characteristic of the diluted sample to change by the first threshold amount and obtaining a second threshold time corresponding to the amount of time elapsed for the solution characteristic of the diluted sample to change by the second threshold amount;
• and
• determining a sample preparation time corresponding to the amount of time necessary for the infectious agent within the diluted sample to reach the defined concentration based on the first threshold time, the second threshold time, concentration data from the look-up table, and the defined concentration.