• Diagnosis of inherited metabolic disorders
• Wherever possible, discuss biopsy and arrangements with Department of Newborn Screening and Biochemical Genetics, Birmingham Children's Hospital 0121 333 9942
  
  • this should include discussion about which specimen bottles and transport medium to use
  • confirm instructions for storage and transport with your local laboratory

• Forceps: fine dissecting forceps
• Cotton wool balls and gallipots
• Dressing towel
• Plastic apron
• Size 15 scalpel blade and no. 3 handle
• 25 G needle (orange top)
• 23 G needle (blue top)
• 21 G needle (green top) for drawing up lidocaine
• 2 mL syringe
• Cleaning solution as per unit policy 
• Lidocaine 1%
• Bottles of culture medium 
• Sterile gloves
• Steri-Strip™ 
• Dressings:
  
  • 1 small transparent dressing (e.g. Tegaderm™/Opsite)
  • gauze swabs
  • elasticated cotton or other bandage

• ≥1 mm x 1 mm of skin (ideally 2 mm x 2 mm) from preferred site (e.g. inner side of forearm or posterior aspect just above elbow)
  
  • choose site carefully as even a small scar on coloured skin will be very obvious
  • if post-mortem, take skin from over scapula as this leaves less obvious damage (see Post-mortem specimens)

Consent

• Inform parents of reason for biopsy, explain procedure and risks including:
  
  • healing and scarring
  • possibility of contamination 
  • poor growth
• Obtain and record written consent (see below for post-mortem sampling)

Technique

• Wash hands and put on apron and sterile gloves
• Cleanse site
  
  • ensure cleaning fluid does not pool beneath baby
• Sedation if appropriate
• Inject lidocaine 1%, a little intradermally and remainder subcutaneously to anaesthetise an area 1.5 x 1 cm
• Wait 5 min to ensure site anaesthetised
• Cleanse again, wipe off and dry using sterile cotton wool or gauze swabs

Method A

• Using fine forceps, grip a fold of skin between blades so that a length of skin 3 mm x 2 mm protrudes
  
  • slice off in 1 stroke by running scalpel blade along upper edge of forceps blades
  • if skin too thick or oedematous to grip, proceed to Method B

Method B

• Pierce skin with 23 or 21 G needle and lift to produce ‛tenting’
  
  • cut off tip of tent to produce a round ‛O’ shaped piece of skin approximately 2 mm 
• Place into culture medium bottle immediately (lid of bottle removed by assistant for shortest possible time)
• Complete request form with:
  
  • clinical details
  • date and time of sampling

Dressing wound

• Although it may bleed freely, wound is usually partial thickness and should not require stitching
  
  • apply pressure to stanch bleeding
  • apply Steri-Strip™ and sterile dressing, bandage if necessary
• Remove bandage after a few hours, but leave dressing for several days
• Reassure parents that scar, when visible, will be seen as a fine line

Transport

• Once sample taken, send to inherited metabolic diseases laboratory as soon as possible
  
  • if unable to arrange transport immediately, store sample at +4°C for maximum of 12 hr before despatch, do not freeze sample

• In accordance with Human Tissue Act, post-mortem samples must be taken only on licensed premises (or satellites thereof). Check with your pathology laboratory manager

• Full written consent required for post-mortem biopsy samples 
• Take 2 biopsies from over scapula (as this leaves less obvious damage) as soon as possible after death, ideally before 48 hr have elapsed
• Send sample to inherited metabolic diseases laboratory immediately, or store at +4°C before dispatch for maximum of 12 hr, do not freeze
• Include clinical details, date and time of sampling, and date and time of death on request form