This is optional and should only be performed if the patient gives additional optional consent.
Urine is transferred into a cryovial and frozen without any processing steps
Stool is transferred into a cryovial containing RNALater (pre prepared at UCL) and shaken for a few seconds before freezing.
In the RCT 1 frozen whole blood sample (purple top, EDTA) per patient is required plus a green top (heparin) blood sample on days 1,5 and 10 for each patient. The green top sample should be processed in the laboratory and plasma removed and frozen. Weekends are excluded from sample collection and if a collection day falls at the weekend the sample should be taken on the closest day possible.
Frozen samples will be transferred to UCL at the end of the study
For full guidance see