DEN-1B McFarland densitometer

Densitometer DEN-1 and DEN-1B is designed for measurement of cell suspension's turbidity in the range 0.3–5.0 (DEN-1); 0.0–6.0 (DEN-1B) McFarland units (100 x 10⁶–150 x 10⁷ cells/ml; or 0–180 x 10⁷ cells/ml correspondingly). DEN-1 and DEN-1Bprovide the opportunity to measure solution turbidity in a wider range(up to 15.0 McFarland units) however, it is necessary to remember thatin this case the standard deviation values increase.

Adensitometer is used for measurement of cell concentration (bacterial,yeast cells) during fermentation process, determination ofmicroorganism sensitivity to antibiotics, microorganism identificationusing various test-systems, for measurement of absorption at thedefinite wavelength, as well as for quantitative estimation ofconcentration of colour solution, absorbing green light.

Theoperation principle is based on measurement of optical density withdigital presentation of results in McFarland units. The unit iscalibrated at the factory and keeps calibration without power supply.However, if necessary it is possible to calibrate the unit by 2–6points in 0.5–5.0 McFarland unit range. Both commercial standards
(e.g. produced by BioMerieux, Lachema, etc.) and the cell suspensionsprepared in a laboratory can be used for calibration.

Following calibration kits are available on request:
• CKG16 for glass tubes with diameter 16 mm;
• CKG18 for glass tubes with diameter 18 mm.

Two versions of the product are available:
1. DEN-1 powered from external energy supply;
2. DEN-1B powered both from external energy supply and from
batteries (АА). Besides, DEN-1B operates with higher precision
of measurements (up to 0,01 McF).