In this task, you are given a sentence. You are expected to write the name of the organism substances in the body mentioned in the input. Although there might be several correct answers, you need to write one of them.

Q:  ( B ) Real - time PCR was performed on total RNA samples from the human brain regions known to express MOR1 .

A: samples
****
Q:  Perhaps the increasing use of hybrid methodologies to concentrate adducts followed by specific chemical analyses will allow such adducts to be monitored more precisely .

A: concentrate
****
Q:  Subjects were excluded from analysis if they withdrew consent or if there was inadequate sample left for PCR testing .

A:
sample
****