Table 2.

Strengths and weaknesses of sample type and recommendations for optimisation

+++ Best, ++ better, + acceptable	Biopsy	Swab	Canister/Drain fluid	Absorption and extraction
Ease of sample collection		++ Technique critical	+++	+++
Cost		+++	+++ Not considering the cost of the therapy itself	+++ Depends on collection and preservation supplies
Patient comfort		++	+++	++
Sample quality and consistency	+++ Procedure most likely performed by highly trained personnel	+++ When using Z technique and correct preservation methods	+++ When comparing samples from the same patient over time	+++ Collection and processing technique critical. Well matched to point‐of‐care diagnostics
Gene expression/PCR	+++ Samples snap frozen with RNase inhibitors
Bioburden	+++ Samples stored, processed and analysed for both aerobic and anaerobic organisms	++ Samples stored, processed and analysed for both aerobic and anaerobic organisms
Biomarker analysis		+ Samples frozen with protease inhibitors	+++ Samples frozen with protease inhibitors. Take into consideration dilution of protease inhibitors over time. Samples should be compared only with other samples collected in the same manner (NPWT, surgical drain)	++ Samples frozen with protease inhibitors. Whatman paper discs, Periopaper. Would be useful to develop collection materials specific to this purpose

PCR, polymerase chain reaction; NPWT, negative pressure wound therapy.