Patent ID: 7138061

Claim:
A method for a user to perform low pressure liquid chromatography, comprising: placing at least one of a material to be analyzed or a chromatographic packing material in a tubular polymer container having an outlet port located at a downstream end of the container and configured for use with chromatographic equipment, the container having container threads formed on an upstream end of the container; threadingly engaging threads on a polymer cap with the container threads, the cap having an inlet port on an upstream end of the cap; and sealing the cap to the container by tightening the threads and engaging a seal between the cap and the container, the seal providing a fluid tight seal below about 100 psi suitable for LPLC use, wherein the sealing step comprises abutting first and second oppositely inclined surfaces on the cap with first and second oppositely inclined surfaces on opposing sides of a lip of the container, the abutting surfaces being generally aligned.