Primers are short pieces of DNA that are made in a laboratory. Since they're custom built, primers can have any sequence of nucleotides you'd like. In a PCR experiment, two primers are designed to match to the segment of DNA you want to copy.
One of the first symptoms of trigger finger is soreness at the base of the finger or thumb. The most common symptom is a painful clicking or snapping when bending or straightening the finger. This catching sensation tends to get worse after resting the finger or thumb and loosens up with movement.
For other uses, see Triggerfinger (disambiguation) . Trigger finger, trigger thumb, or trigger digit (also a sub-set of stenosing tenosynovitis) is a common disorder characterized by catching, snapping or locking of the involved finger flexor tendon, associated with dysfunction and pain.