How to complete the saliva sample and “scratch and sniff” smell identification test

If you are participating in the study for the first time you will receive:

1. A yellow return padded envelope with pre-paid postage and addressed back to the study team
2. A plastic box containing the Isohelix – DNA saliva kit
3. A small plastic DNA Genotek Bio- specimen bag (to put the completed specimen in)
4. A white envelope containing 4 Smell Identification test booklets and a pencil

How to complete the saliva sample

This is labelled "GeneFix” and is a self-collection kit that provides all you need along with the following instructions for collecting and stabilizing your saliva specimen. (Please note: if you have a collection kit which is labelled "Oragene - DNA", you can find an instruction video here)

Before giving the sample please:

1. Do not eat, drink, smoke, chew gum or brush your teeth for 30 minutes before giving your saliva sample.
2. Do not tip out the fluid in the tube. Please check that the fluid level is at 2ml. This is the stabilising fluid and is essential for preserving your sample.

You can watch a short demonstration film here about how to give the sample:

Most people take between 2 and 5 minutes to deliver a saliva sample following steps 1 to 5.

You can read the instructions here:

1. Remove the cap from the tube and keep the cap for later use. Screw the collection funnel on to the tube.
2. Spit into the funnel until the level of liquid in the tube, not including bubbles, reaches the 4ml line.
3. Unscrew the funnel from the tube.. Use the cap to close the tube tightly.
4. Shake the capped tube for 5 seconds to mix with stabilising fluid. Discard or recycle the funnel.
5. Open the small plastic biohazard bag, and place the absorbent sheet and specimen tube inside. Roll this up and place back in the plastic box. Place this in the yellow padded freepost envelope.

Please put the plastic specimen bag with your specimen inside the yellow padded envelope.

How to complete the “Scratch and Sniff” Smell Identification Test

There are four separate booklets that you will find in the white envelope titled “The Smell Identification Test” along with a pencil. Each booklet contains ten separate tests that you can use the pencil to lightly scratch and follow these instructions:

In the post you will receive an envelope containing:

1. Fill in the information on the back of EACH booklet with the enclosed pencil. Please print clearly.
2. Beginning with page 1 of the first booklet (Booklet 1.) use the enclosed pencil to scratch the brown label from left to right several times. This will release an odour. Do not over-scrape the label.
3. Sniff the scraped label and completely fill in the circle corresponding to your smell experience in the column on the right AND ALSO ONLINE. If the odour you smell is not represented, mark the answer closest to the experience. If no smell is present, guess and mark one answer. PLEASE MARK AN ANSWER FOR EACH QUESTION (EVEN IF YOU SMELL NOTHING) TO MAKE THE TEST VALID.
4. After answering all 10 questions in this booklet, complete the other three booklets in order (i.e., from 2 to 4)
5. Place the four completed books and pencil in the yellow pre-paid addressed envelope.
6. Please be sure all 40 questions are answered and the information is filled out on the back of each booklet.

Please put both the completed saliva sample and four booklets in the yellow envelope, seal and post. If this is not your first year in the study we will only send you the smell kits as we only need one saliva sample. In some participants who we think may have difficulty completing the smell test we will send you the saliva collection kit only in the first year. This envelope is Pre-paid and is labelled:

FREEPOST UNIVERSITY COLLEGE LONDON

(Rapsodi RFH)