Stability of archived liquid-based cervical cytologic specimens

Philip E. Castle, Diane Solomon, Allan Hildesheim, Rolando Herrero, M. Concepcion Bratti, Mark E. Sherman, Ana Cecilia Rodriguez, Mario Alfaro, Martha L. Hutchinson, S. Terence Dunn, Jane Kuypers, Mark Schiffman

Research output: Contribution to journalArticlepeer-review

48 Scopus citations


BACKGROUND. Exfoliated cervical cell specimens collected in PreservCyt®, a methanol-based medium used in ThinPrep® liquid-based cytology, have been archived in epidemiologic studies. However, long-term DNA stability and cytologic stability of these biospecimens have not been evaluated. METHODS. Cervical specimens were collected into PreservCyt from participants in a natural history study of human papillomavirus (HPV) infection and cervical carcinoma in Guanacaste, Costa Rica (1993-2000), and stored at ambient temperatures. Thirty specimens classified as low-grade squamous intraepithelial lesions by liquid-based cytology were randomly chosen from each collection year (except for 1994) and selectively assessed for molecular and cytologic stability. Specimens were tested in 2001 for 1) HPV DNA by the Hybrid Capture 2 test, 2) β-globin DNA by polymerase chain reaction amplification of multiple length fragments (268, 610, and 1327 bp), and 3) nuclear preservation by visual inspection of newly made liquid-based cytology slides. All testing was done masked to year of collection. Associations of stability and storage time were evaluated using standard contingency tables and chi-square tests for trend. RESULTS. Human papillomavirus DNA, as detected by the Hybrid Capture 2 test, was unaffected by storage time. Stability of β-globin DNA (PTrend < 0.0001) and nuclear preservation (PTrend < 0.0001) declined with increasing storage time. Approximately 15% of specimens could not be amplified for any β-globin DNA fragment after 5 years of storage (collected in 1996). In addition, cytology slides made from 41% specimens were rated as marginal (32%) or unsatisfactory (9%) after 8 years of storage (collected in 1993). CONCLUSIONS. Cervical specimens archived in PreservCyt underwent partial DNA and cytologic degradation after several years of storage. Methodologic studies to optimize long-term storage of cervical cells for epidemiologic studies of cervical carcinoma are needed.

Original languageEnglish (US)
Pages (from-to)89-96
Number of pages8
Issue number2
StatePublished - Apr 25 2003
Externally publishedYes


  • Archival
  • DNA
  • HPV
  • Liquid-based cytology
  • Stability

ASJC Scopus subject areas

  • Oncology
  • Cancer Research


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