Bob Friedel wrote:
> McFarland Standards are composed of Barium Sulfate suspensions (scale 1-10).
> You will also need a Wickerham card to compare the McFarland standard with
> the organism suspension. See Difco Manual 10th edition, p. 565, 1984.
>> They can be purchased for $5.45 each from Hardy Diagnostics
Also from BioMerieux