Method of sampling, amplifying and quantifying segment of nucleic acid, polymerase chain reaction assembly having nanoliter-sized sample chambers, and method of filling assembly

A method comprising:

• providing a sample containing at least one target nucleic acid molecule to be amplified and constituents for enabling amplification of the target nucleic acid molecule;
• loading the sample into a device, said device having multiple sample chambers;
• subdividing the sample in the device into a plurality of sample portions, one sample portion in each of the multiple sample chambers, wherein at least one of said sample portions loaded into a respective sample chamber includes said at least one target nucleic acid molecule;
• subjecting the sample portions loaded into the respective sample chambers to a homogeneous assay for detecting the amplified product including conditions under which amplification of said at least one target nucleic acid molecule occurs and a detectable amplified product of each target molecule in the sample chambers is formed;
• detecting amplified product in said sample chambers;
• and
• determining the number of said sample chambers that contain a sample portion from which said amplified product is formed, wherein
• said sample chambers each have one or more dimensions such that the sample chambers that contain at least one target molecule before amplification attain a detectable concentration of amplified product in said sample chambers after a single round of amplification.