The ornamental design for saliva collector and isolator, as shown and described.
FIG. 1 is a first perspective view, from above, of a saliva collector and isolator, illustrating the new, original, and ornamental design;
FIG. 2 is a second perspective view, thereof, from below;
FIG. 3 is a side elevation view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof; and,
FIG. 6 is a side elevation view thereof.
The dash dot lines immediately adjacent to the claimed area in FIG. 5 represent the boundaries of the claimed design. The dashed lines in the figures illustrate the portions of the design that form no part of the claimed design. None of the broken lines form any part of the claimed design.