Β. Braun's BIOSTAT* laboratory fermenters have proven themselves extensively in the most prestigious laboratories of Europe. Now they're available for the first time in the United States and give you a firstclass alternative to other systems.
The finest fermenter in the world arrives.
The essential virtues of BIOSTAT fermenters center around their un excelled monitoring and regulating features, along with exceptional ver satility. Rugged, continuous-duty systems, BIOSTAT fermenters fulfill all re quirements for the submersed, con tinuous growth of microorganisms on the chemostat and batch principle. Reproducibility is assured through precisely-controlled parameters: temperature, stirring speed, nutrient feeding, anti-foaming, acidity, alka linity, oxygenation, gas flow, and humidity control.
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Sterility? Our multiple sealing sys tems protect against contamination. The modular nature of the system allows us to tailor an instrument to your precise requirements. Let us convince you. Contact:
B. Braun Instruments 805 Grandview Drive South San Francisco, CA 94080 Phone (415) 589-9217 CIRCLE 25 ON READER SERVICE CARD
PRODUCTS ANALYSIS 99 pages of answers
Spectrocell
to vour analytical needs Now, under one cover — you will find every t h i n g for the analyst. Hach methods and equipment bring combined ease-of-use and accuracy t o the laboratory and plant. • Labware and accessories: selected for single source convenience. • Lab and portable instruments. • On-line analyzers: for raw, process, and effluent water. • Test kits: 1 22 kinds for all common testing parameters. • Analytical chemicals: high purity and prepared reagents. • Technical literature access return cards. call today for your free copy: 1 -800-525-5940 Hach Chemical Company Box 3 8 9 Loveland, Colorado 8 0 5 3 7
HACH
CIRCLE 91 ON READER SERVICE CARD
GUM
Precision Glass Products Co. manufactures precision spectrophotometer cells through a unique " D F " (direct fusion) technology, pro ducing virtual one—piece quartz cells, for tolerance to heat, cold, and shock—at 25 to 4 0 % below market prices.
The highest quality standard IR and UV quartz spectrophotometer cells
at the lowest prices Send for our "Spectrocell" catalogue for a description of cells in stock, or send specifications for custom work. All cells are made in the U.S. and shipped in cushioned plastic boxes. *1 cm. standard quartz cell
Precision Glass Products Co. P.O. Box 145 Oreland, P a , 19075 (215) 885-0145 CIRCLE 175 ON READER SERVICE CARD
ANALYTICAL CHEMISTRY, VOL. 52, NO. 14, DECEMBER 1980 · 1605 A
