Abstract: A diagnostic test device to perform a test on a biological or environmental sample is provided. In one aspect, the diagnostic test device includes a sample preparation reservoir; a dispensing mechanism that includes a sealing member and a piercing member; and at least one diagnostic test reservoir separated from the sample preparation reservoir by a seal. A predetermined volume of fluid is defined between the sealing member, the piercing member, sides of at least one chamber defined by the sample preparation reservoir, and the seal when the sealing member engages the sides of the at least one chamber. The piercing member disrupts the at least one seal to dispense the predetermined volume of fluid to the at least one diagnostic test reservoir. The sealing member is configured to directly contact the sides of the at least one chamber as the seal is disrupted.

Abstract: Disclosed herein include methods, compositions, and kits suitable for use in sample testing. The sample testing systems can comprise a cartridge body to receive a sample, at least one reaction chamber coupled to the cartridge body, and at least one seal between the cartridge body and the at least one reaction chamber. The sample testing system can comprise a sample dispensing mechanism operable to disrupt the at least one seal to dispense a predetermined sub-volume of sample fluid from the cartridge body into the at least one reaction chamber. The sample dispensing mechanism can comprise a dispense rod comprising at least one piercing tip that disrupts the at least one seal by forming at least one opening therein. The piercing tips can comprise a geometry configured to generate a large opening in the at least one seal.