Angeline,
For my baby, for each allergen the technician will put a small drop on the baby's hand, use scraper to remove a tiny area of skin (no bleeding, dun worry), wait 15min for results.
For me, will draw blood coz need to test on 100+ types of allergen.
I hav no idea the package size tt provided by hospital. U may need to check wif them.
The one tt i will go for it is for research sampling and I can get the results from them. It is done by my friend for free, she will arrange nurse to draw my blood. Heard it will cost 300-400bucks if do it in hospital.