A PNEUMATIC DEVICE FOR RAPID LOADING OF DNA-SEQUENCING GELS

This work describes the design and construction of a device that Facil itates the loading of DNA samples onto polyacrylamide gels for detecti on in the Perkin Elmer/Applied Biosystems (PE/ABI) 373 and 377 DNA seq uencing instruments. The device is mounted onto the existing gel casse ttes and makes the process of loading high-density gels less cumbersom e while the associated time and errors are reduced. The principle of o peration includes the simultaneous transfer of the entire batch of sam ples, in which a spring-loaded air cylinder generates positive pressur e and flexible silica capillaries transfer the samples. A retractable capillary array carrier allows the delivery ends of the capillaries to be held up clear of the gel during loader attachment on the gel plate s, while enabling their insertion in the gel wells once the device is securely mounted. Gel-loading devices capable of simultaneously transf erring 72 samples onto the PE/ABI 373 and 377 are currently being used in our production sequencing groups while a 96-sample transfer protot ype undergoes testing.