Automated capillary injector

Abstract

Abstract A pressure integrated apparatus and process for the measured injection of sample into a capillary for electrophoresis is disclosed. Preferably the cap­illary is mounted in a serpentine path to a cartridge body having a bottom. The capillary, previously filled with electrolyte depends a distance below the bottom of the cartridge and has its periphery sealed to the car­tridge. Typically, the cartridge is registered at the depending capillary to a vial of sample. The vial of sample is moved into substantial gas tight relation with the cartridge so that the depending capillary is below the surface of liquid within the sample vial. The vial is then communicated to a source of substan­tially constant fluid pressure in the order of 1 lb./inch². At the same time, a pressure gauge monitors the pressure of the vial and outputs a signal to integration apparatus such as a microprocessor. By time integration of the area under a pressure curve, precise monitoring of the amount of fluid introduced into a capillary occurs. Assuming a total capillary capacity of several micro­liters, injections of sample in the order of 5 nano­liters with an accuracy of plus or minus 2% is possible. In one embodiment, a reusable vial cap is provided with four resiliently deflectable flaps sur­rounded by an integral O-ring sealing region. The cap can cooperate with downwardly dependent fingers on a lever arm to make an opening for insertion of a capillary and electrode.

Inventors

• 👤 Victor Paul Burolla

Bibliographic Details