Which tubes do not contain anticoagulants?

The tubes that do not contain anticoagulants are those typically used for serum chemistry tests. The option indicating red, royal blue with a red stripe, and tiger top tubes reflects this accurately.

Red-top tubes are primarily used to collect serum for various serological tests and do not contain anticoagulants, thereby allowing the blood to clot. The royal blue tube with a red stripe also corresponds with specific tests requiring serum. Similarly, the tiger-top tube, which has a gel separator, allows for blood to clot and is used for serum collection as well.

In contrast, the other options include tubes that do contain anticoagulants used to preserve blood in its liquid state for certain types of analyses, such as those requiring whole blood or plasma samples.