Question: how to do tb injection?
Answer: Locate and clean injection site 5–10 cm (2–4 inches) below elbow joint. Place forearm palm-up on a firm, well-lit surface. ... 
Prepare syringe. Check expiry date on vial and ensure vial contains tuberculin PPD-S (5 TU/0.1 ml). ... 
Inject tuberculin (see Figure A3.1) ... 
Check injection site. ... 
Record information.