Use MIC/MBC Ratio when you need to compute the ratio of minimum bactericidal concentration to minimum inhibitory concentration; a value of 1 to 4 indicates a bactericidal agent. Enter MIC and MBC using the definitions and units below so the result can be reproduced.

MIC

Minimum inhibitory concentration; must be greater than zero.

MBC

Minimum bactericidal concentration; must not fall below the MIC.

The published tool contract uses this rule: Compute the ratio of minimum bactericidal concentration to minimum inhibitory concentration; a value of 1 to 4 indicates a bactericidal agent.^[1]

MBC/MIC ratio

MBC divided by MIC.

A ratio or percentage can conceal the scale of its numerator and denominator and becomes sensitive to measurement error when the denominator is small.

Retain the original MIC and MBC values and their units alongside the result. 260/230 Ratio is useful when you instead need to calculate the A260/A230 purity ratio used to detect organic compounds and salts carried over from extraction. 260/280 Ratio provides another view by helping you calculate the A260/A280 purity ratio used to assess nucleic acid contamination by protein.

• 260/230 Ratio

  Calculate the A260/A230 purity ratio used to detect organic compounds and salts carried over from extraction.

• 260/280 Ratio

  Calculate the A260/A280 purity ratio used to assess nucleic acid contamination by protein.

• APTT Ratio

  Compute the activated partial thromboplastin time ratio as the patient APTT divided by the control APTT.