Phlebotomy Technician Practice Exam (NCPT/CPT)

What is the order of draw for a PTT and H&H?

1. Light Blue, Red

2. Lavender, Light Blue

3. Light Blue, Lavender

4. SST, Light Blue

The correct answer is: Light Blue, Lavender

The correct order of draw for a PTT and H&H is Light Blue, Lavender. This is because the light blue tube contains sodium citrate, an anticoagulant, which is necessary for coagulation tests like PTT. The lavender tube contains EDTA, an anticoagulant that is necessary for hematologic tests like H&H. Option A is incorrect because the red tube does not contain an anticoagulant, thus it is not ideal for these tests. Option B is incorrect because the light blue tube should be drawn before the lavender tube. Option D is incorrect because the SST tube contains a gel separator and does not contain an anticoagulant like sodium citrate or EDTA, making it unsuitable for these tests.