McFarland Latex Standards

Turbidity standards for adjusting densities of bacterial suspensions

SUMMARY

McFarland Standards provide a reference for standardization of bacterial suspensions used for susceptibility testing and other procedures that require a standardized inoculum. Original McFarland Standards (Cat. no. HDMS05-HDMS6) are prepared by adding barium chloride to sulfuric acid resulting in a barium sulfate precipitation.

The McFarland Latex Standards (Cat. no. HDML05-HDML6 and HDML8) are prepared from suspensions of uniform latex particles with similar absorbance values as the original barium sulfate standards. The latex standards are prepared by suspending latex particles in a buffer solution. Sodium azide is added as a preservative. The standards are adjusted to an acceptable absorbance range with a one centimeter light path set at 625nm. Adjusting a bacterial suspension turbidity to a McFarland Standard produces bacterial counts in an expected range. As with the barium sulfate standards, a 0.5 McFarland Standard is comparable to a bacterial suspension of 1.5 X 10⁸ CFU/ml.

The stability of McFarland Latex Standards allows for a significantly longer shelf-life than the original barium sulfate standards due to reduced light sensitivity.

Available McFarland Standard 0.5,1, 2, 3, 4, 5, 6, 7, 8 (16x100mL, 8mL)

Brochure

Ordering Details: -

Product Code: HDML05          McFarland Latex Equivalent 0.5 HDx, 16 x 100mL, 8mL

Product Code: HDML1            McFarland Latex Equivalent 1 HDx, 16 x 100mL, 8mL

Product Code: HDML2            McFarland Latex Equivalent 2 HDx, 16 x 100mL, 8mL

Product Code: HDML3            McFarland Latex Equivalent 3 HDx, 16 x 100mL, 8mL

Product Code: HDML4            McFarland Latex Equivalent 4 HDx, 16 x 100mL, 8mL

Product Code: HDML5            McFarland Latex Equivalent 5 HDx, 16 x 100mL, 8mL

Product Code: HDML6            McFarland Latex Equivalent 6 HDx, 16 x 100mL, 8mL

Product Code: HDML8            McFarland Latex Equivalent 8 HDx, 16 x 100mL, 8mL