Table 1.

Pertinent publications on wound exudate collection and analysis

Reference	Wound type	Wound fluid collection method	Absorbent material	Processing	Storage	Analysis
Wysocki and Grinnell 72	Chronic leg ulcers	Fluid collected from under vapour‐permeable film Tegaderm™ (3M) in place for 4–12 hours with a tuberculin syringe and 20‐gauge needle		Centrifugation for 4 minutes at 11 600 g	−70°C	Western blot
Dvonch et al. 63	Surgical wounds	Fluid collected from negative pressure drainage system reservoir		Centrifugation for 10 minutes at 5000 g	−70°C	Western blot
Bucalo et al. 66	Chronic wounds	Fluid collected from under polyurethane membrane (Hollister) or vapour‐permeable film (Tegaderm™, 3M) in place for 24 hours		Centrifuged at 800 g and sterile filtered through 0·2‐µm filters	−20°C	Effects on cell proliferation and viability
Cooper et al. 83	Pressure ulcers	Dextranomer beads in place for 24 hours	Dextranomer beads	1 g of saturated beads mixed with an equal volume of PBS for 12 hours in a vertical shaker at 4°C. Centrifuged at 1000 g for 5 minutes at 4°C	−80°C	Total protein (Bradford assay) cytokine analysis (ELISA)
Harris et al. 67	Venous leg ulcers	Ulcer bed wiped clean with sterile saline. Fluid collected from under vapour‐permeable film Tegaderm™ (3M) in place for 4–6 hours with needle and syringe		Centrifuged at 12 000 g for 3 minutes. Diluted to 10% with sterile saline and filtered through 0·2‐µm filters	−60°C	Total protein (Biuret method). Collagenase activity. Fibronectin degradation. IL‐1 and IL‐6 bioassays
Trengrove et al. 71	Chronic lower leg ulcers	Patient fasted beginning at midnight. Transparent occlusive dressing (Opsite™, Smith & Nephew) applied at 8 am. Patient's leg placed in a dependent position and patient encouraged to drink 1 l of water. Fluid aspirated from under the dressing at 1 hour and transferred into Greiner Vacuette vacuum serum collection tubes				Osmolarity. General biochemical entities
Fivenson et al. 77	Chronic venous leg ulcers	Each wound was dressed with a layer of non‐adherent dressing, covered by a hydrofoam pad (Allevyn®, Smith & Nephew). The central 2 cm diameter of the hydrofoam dressing directly overlying the ulcer centre was collected and stored at −70°C	Allevyn®	Allevyn® dressing was homogenised in 2 ml of sample buffer (sterile PBS containing protease inhibitors) followed by sonication	−70°C	ELISA
Yager et al. 73	Venous Stasis and pressure ulcers, surgical wounds	Fluid collected from under vapour‐permeable film Tegaderm™ (3M) in place for 4–8 hours with a tuberculin syringe		Centrifuged at 14 000 g for 15 minutes at 4°C	−20°C	ELISA, Western blot
Nissen et al. 65	Surgical wounds	Fluid collected from closed negative pressure 69 drains		Centrifuged at 1300 g for 10 minutes	−70°C	VEGF FGF‐2 ELISA. Endothelial cell chemotaxis
Hoffman et al. 64	Venous leg ulcers	Wound fluid was manually extracted from an absorptive dressing soaked in ice‐cold PBS (10–20 ml) containing 0·02% sodium azide. Mastectomy wound fluid was collected over a 24‐hour period into a Bellova drainage unit	Absorptive dressing	Centrifuged at 13 000 g for 10 minutes	−70°C	Plasminogen degradation and plasmin generation
Simonsen et al. 85	Diabetic foot ulcers	Microdialysis using probes made of 3 cm long sections of artificial dialysis kidney (Gambro GSF+12) and nylon tubing placed in situ via a G18 cannula				Glucose and lactate (YSI 2300 glucose‐lactate analyser; Yellow Springs Instruments, Yellow Springs, OH)
Mendez et al. 78	Venous ulcers	Foam wafer occlusive dressing (Allevyn®, Smith & Nephew), which was placed over the ulcer and covered by a paste bandage (Unna's boot) and a compression wrap. Dressings were changed weekly, and wound fluid was extracted from the foam wafer with a sterile syringe with a 20‐gauge needle	Foam wafer occlusive dressing (Allevyn®, Smith& Nephew)	Diluted 1:10 with DMEM and filtered through 0·2‐µm filter	−70°C	Fibroblast proliferation. TNF‐α concentration (ELISA)
Tarlton et al. 81	Venous leg ulcers	Absorptive filters of 1 cm 2 dimensions were prepared from Whatman 54 paper sterilised in ethanol, oven‐dried at 60°C and pre‐weighed in sterile 2 ml Apex tubes. Sterile Tegapore™ mesh (3M) was cut into 4 cm2 segments. The mesh was placed on the ulcer and wound fluid absorbed through it into the collection filter excluding solid material, which would otherwise compromise subsequent quantification	Whatman 54 paper	Filters were incubated in extraction buffer (0·1% Brij 35 (BDH, Poole, UK) in 20 mM triethanolamine) added 50:1 (v/w) for 4 hours with agitation	−20°C	Zymography. Type I collagen C propeptide content (ELISA)
James et al. 68	Chronic leg ulcer	Leg kept dependent for 30–40 minutes. Fluid collected from under a transparent occlusive dressing (Opsite™, Smith & Nephew) in place for 4–8 hours with syringe and needle		Centrifuged at 8000 g for 5 minutes	−70°C	Total protein (Biuret method). Biochemical analysis
Cullen et al. 76	Diabetic foot ulcer	RELEASE® (Johnson & Johnson Ltd.) dressing was cut to the size of the wound, placed in contact with the ulcer bed for 24 hours and covered with BIOCLUSIVE® (Johnson & Johnson Ltd.), an occlusive film. The dressing was then removed and frozen at −70°C until elution of wound fluid		Wound fluid was eluted from the RELEASE dressing by incubating the sample in 1 ml of wash buffer/cm2 dressing (0·1 M Tris–HCL pH 7·4 containing 0·1% Triton X‐100) for 2 hours at 4°C. Dressing compressed against the side of a container and eluent removed	−70°C	Total protein (Bradford). Protease activity. Zymography
Lauer et al. 69	Venous leg ulcers	Ulcers were covered with a semipermeable polyurethane film (Hyalofilm, Hartmann, Heidenhein, Germany) for a maximum of 8 hours. Fluid was assumed to be collected from beneath the dressing although not stated		Centrifuged at 13 000 g for 10 minutes at 4°C	−80°C	VEGF levels (ELISA), Western blot). Plasminogen presence and plasmin activity
Moseley et al. 80	Venous leg ulcers. Chronic wounds	Absorptive filters (1 cm2) were prepared from Whatman 54 paper. Sterile Tegapore™ mesh (3M) was cut into 4 cm2 segments; absorptive filters placed inside and the mesh thermally sealed. Each filter paper mesh was autoclave‐sterilised and oven‐dried. A filter paper mesh was placed onto the surface of each wound until filter paper was saturated	Whatman 54 paper	Wound fluid was recovered by removing the filter papers from the mesh and eluting with 1 ml PBS at 4°C for 1 hour	−20°C	Total protein assay (Bio‐Rad). Total protein carbonyl and malondialdehyde content. Western blot. Total antioxidant capacity
Fernandez et al. 75	Chronic venous leg ulcers	Ulcers were washed with sterile water and covered with an occlusive dressing. Exudate was collected from under the dressing after 30 minutes to 1 hour by washing with 1 ml of saline		Centrifuged at 14 000 g for 10 minutes. Filtered through 0·45‐µm cellulose acetate filters. Samples from five patients were pooled and aliquoted. Immunodepletion	−80°C	Total protein, Western blot, 2D gel electrophoresis and proteome fractionation, liquid chromatography/mass spectrometry
Moues et al. 87		Wound fluid was collected daily for up to 10 days using sterile polyvinylidene fluoride filters (Durapore membrane filters, Millipore®, Amsterdam, The Netherlands, 47 mm area and 0·1 µm thick). Four filters per wound per dressing change were collected after full saturation (never exceeding 20 minutes)		Filters were extracted in 1 ml of cold (4°C PBS (pH 7·4) for 10 minutes with gentle rocking followed by centrifugation at 4000 rpm for 10 minutes at 16°C. Supernatant was aliquoted and stored	−20°C	ELISA, Biotrack Activity Assay system
Rayment et al. 70	Chronic venous ulcers	Wounds washed with saline. Wound fluid collected from under occlusive dressing in place for 30 minutes to 1 hour by washing with 1 ml of saline. Wound fluid collected from blisters with 26‐gauge needles and syringes		Centrifuged at 14 000 g for 10 minutes. Filtered using cellulose acetate filters	−80°C	Total protein (BCA). Zymography. MMP‐9 levels (ELISA)
Moor et al. 79	Venous leg ulcers	Tegapore™ mesh (3M) placed on wound bed and wound fluid collected by absorption through mesh onto 1 cm2 Whatman 54 paper	Whatman 54 paper	Filters were extracted with 50 :1 (v/w) CAB buffer, pH 7·5 (25 mM Tris–HCl pH 7·5, 200 mM NaCl, 3 mM CaCl2 and 0·03% Brij‐35) overnight at 4°C. The extracts were centrifuged at 10 000 g for 15 minutes at 4°C	−80°C	MMP‐13,1 activity assays (Sensolyte Plus assay kit Anaspec, San Jose, CA). MMP‐8 levels (ELISA). MMP‐2, P levels and activity. Zymography. Western blotting. Multiplex assay
Eming et al. 74	Venous leg ulcers, acute wounds	Wounds were covered with a semipermeable polyurethane film (Hyalofilm, Hartmann, Heidelberg, Germany) for a maximum of 8 hours. It is assumed that fluid was collected from under the dressing		Centrifuged at 13 000 g for 10 minutes at 4°C and supernatants were frozen at −80°C	−80°C	SDS‐PAGE, mass spectrometry, ELISA, dot plots
Wyffels et al. 82	Pressure ulcers	Wound proteins were collected using sterile polyester tipped applicators gently rolled over the wound surface until saturated. The tip of the swab was broken off and placed in a 2 ml vial prefilled with 150 µl PBS (10 mM, pH 7·4)	Polyester tipped applicators	Proteins eluted from the polyester tip by the addition of 350 µl dH2O and vortexed for 30 seconds. The swabs were inverted and all liquid removed from the polyester tip via centrifugation for 10 minutes at 6000 g, swabs were removed and debris pelleted by repeating the centrifugation. Supernatant filtered using spin columns (3‐kDa cutoff) (Millipore, Amicon Microcon® UltracelYM‐3, Billerica, MA)	−80°C	Two‐dimensional gel electrophoresis

ELISA, enzyme‐linked immunosorbent assay; PBS, phosphate‐buffered saline; VEGF, vascular endothelial growth factor, FGF, Fibroblast Growth Factor, DMEM, Dulbecco's Modified Eagle Medium, TNF, Tumor necrosis factor, SDS‐PAGE, Sodium dodecyl sulfate polyacrylamide gel electrophoresis.