With S&S collodion bags you dont lose your concentration.

S&S collodion bags and apparatus are an ideal system for concentrating proteins from cerebral spinal fluid, urine, and other body fluids. In addition, the S&S collodion bag system is used to concentrate strands of R N A or DNA.

Use S&S collodion bags and your fraction collects in the tip of the bag, all together for easy removal without loss. You achieve higher recoveries than with other methods of concentration and dialysis, especially dialysis tubing. S&S bags are ideal for in vitro diagnostic use.

You get more of your sample, too. S&S collodion bags are the only practical method on the market that lets you reduce solutions of protein to near-zero volumes. Each bag provides 10cm- of membrane filter surface. The S&S system permits the widest variety of sample volumes, from less than 10ml up to unlimited volumes using the S&S accelerator. Choice of three grades permits a range of MW retentions—10,000, 25,000 and 75,000. And you can withdraw as little as 10μ1.

The S&S collodion bag system is faster, lets you dialyzc and concentrate simultaneously under a vacuum, and permits you to recover the retentate for further in­vestigation.

S&S collodion bags are inexpensive enough to use once and discard. They're sturdy enough to be cleaned

and rc-used up to 10 times. The full line of apparatus making up the S&S system is inexpensive glassware. The S&S collodion bag accelerator reduces concentration times up to 43 percent, permits continuous concentration of large volumes, permits easy withdrawal of concentrate during dialysis.

For complete informa­tion and specifications send for Instructional Bulletin S-3. Your laboratory supply dealer should have the com­plete system — collodion bags and a p p a r a t u s — i n stock. You can well afford to be caught holding this bag.

Schleicher & Schuell Schleicher & Schuell, Inc. Keene, New Hampshire 03431 Schleicher & Schiill GmbH, D-3354, Dassel, West Germany Schleicher & Schiill AG, 8714, Feldbach ZH, Switzerland

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