AIR HAS ITS USES
BUT NOT WHEN ACCURACY COUNTS
WithMICRO/PETTOR
WE'RE POSITIVE Air is great for inflating bike tires and breathing, but it's not a particularly efficient means of dispensing fluid from a pipet. Air displacement systems leave too much residue in the tip, and depending on viscosity, seriously reduce transfer accuracy. The SMI Positive Displacement MICRO/PETTOR Pipetting System, on the other hand, employs a precision bore capillary in which a precisely manufactured plunger operates to draw fluid into and dispense it from the capillary. The capillary is filled to a pre-set length by the plunger. Be cause there is no air space, the capillary will contain and the plunger will forcibly dispense, the same amount of fluid every time, virtually any viscosity. The plunger tip extends beyond
smi
the end of the capillary assuring complete delivery. And the MICRO/PETTOR system is specifically designed to deliver with 1/2% or less carryover from sample to sample. SMI makes positive displacement pipets for virtually every application—ratings from 1 μ\ to 3 ml. MICRO/PETTORs for many clinical uses; Adjustable Volume MICRO/PETTORs for research; RE/PETTOR®s for repetitive dispensing of reagents. All are accurate; all are economical. We're Positive. And we'll send you a free reprint "How to Use and Check Pipetting Equipment." Check your distributor or call SMI toll free (800) 227-0650, (In California) (800) 772-3937, Area Code (415) 548-8000.
scientific manufacturing industries inc.
800 University Ave., Berkeley, CA 94710 CIRCLE 195 ON READER SERVICE CARD
260 A · ANALYTICAL CHEMISTRY, VOL. 5 1 , NO. 2, FEBRUARY
1979
SMI holds Patent #3815790.
