Improvements in or relating to pipette means.

摘要

This invention is in the field of automatic chemical (more especially bio-chemical) analysis.
<??>It improves accuracy of sampling, diluting and dispensing of liquids, eg blood serum.
<??>A circumferentially compressible tube (10) communicates through the lower of two connecting tubes (22) with a pipette tip, and through the upper with a source of diluent. The tube (10) is compressed circumferentially and elastically by fluid pressure applied through a connector (24) into a space (16) surrounding the tube (10) inside a block (12). Relief of the pressure allows tube (10) to expand and draw a sample into said pipette tip, the sample volume being dependent on the fluid pressure applied. Reapplication of pressure expels the sample from the pipette tip. Any diluent required is supplied through the upper connecting tube (22), and passes out through the pipette tip. It is important for consistency of results that the tube (10) be compressed elestically, and a suitable material for the tube (10) is latex rubber. It may be lined with silicone rubber to reduce moisture absorption.