title: Long term stability of HBsAg, anti-HBc and anti-HCV in dried blood spot samples and eluates.
abstract: BACKGROUND
  Dried blood spots (DBS) are a useful specimen collection tool in situations where venous access is problematic, however, detection of biomarkers from this specimen type is subject to variation depending on storage conditions and storage time.
  
  
  OBJECTIVE
  The objective of this study is to assess the detection of HBsAg, anti-HBc and anti-HCV from DBS after storage.
  
  
  METHODS
  DBS specimens were stored at -70°C, -20°C, 4°C, 22 to 28°C and 37°C either with or without desiccant. Eluates were also prepared from DBS specimens and stored at -20°C and -70°C. DBS cards and eluates were tested for HBsAg, anti-HBc and anti-HCV at baseline on day 0 and thereafter at intervals of 14, 70 and 200 days.
  
  
  RESULTS
  Loss of detection of both HBsAg and anti-HBc was evident by the first time point (14 days) in all storage conditions except for the samples (DBS and eluates) stored at -20°C or -70°C. Both HBsAg and anti-HBc stored under these conditions showed minimal variation up to the final time point (200 days) of storage. The detection of anti-HCV did not differ between the 22 to 28°C, 4°C, -20°C and -70°C DBS nor the -20°C or the -70°C stored eluates over the 200 day time period.
  
  
  CONCLUSIONS
  We suggest that extended storage of DBS intended for downstream testing is best carried out by freezing either the DBS, or eluate, at -20°C or -70°C as soon as possible following collection for optimal detection of HBsAg, anti-HBc and anti-HCV.
authors.affiliation: East of Scotland Specialist Virology Centre, Edinburgh Royal Infirmary, 51 Little France Crescent, Edinburgh, Scotland, UK. Electronic address: g.mcallister@nhs.net.
authors.forename: Georgina
authors.initials: G
authors.lastname: McAllister
authors.affiliation: West of Scotland Specialist Virology Centre, Glasgow Royal Infirmary, Glasgow, Scotland, UK.
authors.forename: Samantha
authors.initials: S
authors.lastname: Shepherd
authors.affiliation: East of Scotland Specialist Virology Centre, Edinburgh Royal Infirmary, 51 Little France Crescent, Edinburgh, Scotland, UK.
authors.forename: Kate
authors.initials: K
authors.lastname: Templeton
authors.affiliation: West of Scotland Specialist Virology Centre, Glasgow Royal Infirmary, Glasgow, Scotland, UK.
authors.forename: Celia
authors.initials: C
authors.lastname: Aitken
authors.affiliation: West of Scotland Specialist Virology Centre, Glasgow Royal Infirmary, Glasgow, Scotland, UK.
authors.forename: Rory
authors.initials: R
authors.lastname: Gunson
mesh_terms: D003890:Desiccation; D006509:Hepatitis B / Q000175:diagnosis*; D006510:Hepatitis B Antibodies / Q000032:analysis*; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D018937:Hepatitis C Antibodies / Q000032:analysis*; D003699:Hepatitis D / Q000175:diagnosis*; D006801:Humans; D055550:Protein Stability; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods; D013048:Specimen Handling / Q000379:methods*; D013696:Temperature; D013997:Time Factors
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D018937:Hepatitis C Antibodies
keywords: Dried blood spots; Eluates; Hepatitis B; Hepatitis C; Storage