BacterTube™ McFarland 0.5 Turbidity Standard

Ready-to-use liquid standard used for bacterial suspension standardization in antimicrobial susceptibility testing.
Code: 08024
Packaging: 50 tubes/ box or as per customer request.
Storage Conditions: 2–8°C.
Transportation: Ambient temperature.
Shelf Life: 6 months from the date of manufacture.

INTENDED USE

BacterTube™ McFarland 0.5 Turbidity Standard is used to standardize the density of bacterial suspensions for antimicrobial susceptibility testing (AST) and other microbiological applications requiring consistent bacterial concentration.

PRINCIPLES

The McFarland standard is a turbid suspension of barium sulfate prepared by mixing barium chloride (BaCl₂) and sulfuric acid (H₂SO₄). When properly mixed, the resulting precipitate provides a reproducible and stable turbidity comparable to a specific bacterial concentration. The McFarland 0.5 standard corresponds to approximately 1.5 x 10⁸ CFU/mL of Escherichia coli ATCC 25922 and other standard bacterial strains used in AST procedures.

Before use, gently mix the tube to ensure an even suspension.
Compare the bacterial suspension in a clear tube against the McFarland 0.5 standard under adequate lighting.
Adjust the bacterial suspension by adding sterile saline or broth if the turbidity is too high or adding more bacteria if the turbidity is too low.
Use the standardized bacterial suspension immediately for antimicrobial susceptibility testing.

Notes:

This product is intended for laboratory use only and should not be used for direct clinical diagnosis.
The McFarland standard must be stored in a light-protected area to prevent degradation.
Over time, precipitation may occur; shake well before use to ensure uniformit

BacterLab ensures the quality of each product batch by testing with ATCC reference strains.

Reference strains	Incubation conditions	Expected results
Eschirichia coli ATCC 25922	16 – 24 hours, 33 – 37°C	The bacterial suspension has a bacterial count of 10⁸ CFU/mL.