FIG. 1 is a front perspective view of a first embodiment of a polymerase chain reaction instrument;
FIG. 2 is a back perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a back view thereof;
FIG. 5 is a side view thereof;
FIG. 6 is a side view thereof;
FIG. 7 is a top view thereof;
FIG. 8 is a bottom view thereof;
FIG. 9 is a front perspective view of a second embodiment of a polymerase chain reaction instrument;
FIG. 10 is a front view thereof;
FIG. 11 is a back view thereof;
FIG. 12 is a side view thereof;
FIG. 13 is a side view thereof;
FIG. 14 is a top view thereof;
FIG. 15 is a bottom view thereof;
FIG. 16 is a front perspective view of a third embodiment of a polymerase chain reaction instrument;
FIG. 17 is a front view thereof;
FIG. 18 is a back view thereof;
FIG. 19 is a side view thereof;
FIG. 20 is a side view thereof;
FIG. 21 is a top view thereof;
FIG. 22 is a bottom view thereof;
FIG. 23 is a front perspective view of the third embodiment of the polymerase chain reaction instrument with the door in an open position;
FIG. 24 is a front view thereof;
FIG. 25 is a back view thereof;
FIG. 26 is a side view thereof;
FIG. 27 is a side view thereof;
FIG. 28 is a top view thereof; and,
FIG. 29 is a bottom view thereof.
The broken lines immediately adjacent the shaded areas represent the bounds of the claim, while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.