FIG. 1 is a top plan view of a unit for retaining and labeling test tubes showing my new design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a rear elevational view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken line showing of the tube is for illustrative purposes only and forms no part of the claimed design.