Cap for vessel for performing multi-stage process

A multi-stage process for reacting a sample in a vessel, wherein the vessel is configured to receive a cap to enclose the vessel interior, the cap comprising:

• i) a body having a cap cavity,
• ii) a spike cap portion connected to the body by a spike cap arm, the spike cap portion comprising a closed top and a spike with a sharp distal end, and
• iii) a driver cap portion comprising a bearing surface, wherein the driver cap portion is connected by a driver cap arm to an upper wall that extends upward from the body, the upper wall being open in the region where the spike cap arm connects to the body,
• wherein the driver cap arm is disposed opposite that of the spike cap arm, and
• wherein the cap is adjustable between a first stage position in which the cap cavity is fluidicly isolated from the vessel interior, and a second stage position in which the cap cavity is fluidicly coupled with the vessel interior, the method comprising the steps of:
• a) providing in the vessel interior a sample mixed with first stage reagents for conducting a first stage reaction;
• b) mating the cap to the vessel to enclose the vessel interior;
• c) conducting the first stage reaction with the sample and first stage reagents in the vessel interior, wherein the first stage reaction is conducted with the cap in the first stage position in which the cap cavity is fluidicly isolated from the vessel interior;
• d) adding second stage reagents stored in the cap cavity to the reaction product of the first stage reaction, wherein the second stage reagents are added by moving the cap into the second stage position in which the cap cavity is fluidicly coupled with the vessel interior and mixing the second stage reagents with the reaction product of the first stage reaction;
• and
• e) conducting a second stage reaction in the vessel interior with the reaction product of the first stage reaction and the second stage reagents.