Excellent for use in microhematocrit determinations Ends can be sealed by flame, sealing clay or caps Manufactured from low-taper, soft glass Tubes are packed in plastic vials with reclosable snap-lock caps to maintain cleanliness Red band on tube indicates heparinization; blue band indicates nonheparinized tube Interior surface of heparinized tubes is evenly coated with ammonium heparin (4 to 7 USP units), which will not interfere with sodium determination Order Info Length: 75mm