# Successful Retrieval of Human Papillomavirus DNA in Veil-Based Collected Female Genital Secretions After Long-Term Storage in Universal Transport Medium

## TL;DR

This study shows that HPV DNA can be successfully retrieved from genital secretions stored for 27 months in a transport medium, even at room temperature.

## Contribution

Demonstrates the long-term stability of HPV DNA in self-collected genital secretions stored in universal transport medium.

## Key findings

- HPV DNA remained detectable and quantifiable after 27 months of storage at −30 °C, +4 °C, and +25 °C.
- Degradation of cellular DNA occurred at positive temperatures but not at −30 °C.
- High accuracy in HPV genotype detection was maintained across all storage conditions.

## Abstract

Background/Objectives: The surveillance of viral strain evolution is needed during prophylactic HPV vaccination programs against cervical cancer and necessitates safely archiving and storing cervical samples while maintaining the long-term stability of HPV DNA to carry out molecular diagnosis. The present proof-of-concept study aimed to assess DNA stability for HPV molecular detection from veils resuspended in a universal transport medium (UTM) and conserved at different temperatures after long-term storage. Methods: The detection and quantification of HPV DNA were evaluated in female genital secretions self-collected using veils and conserved in Cyt-All® UTM at −30 °C, +4 °C, and +25 °C after long-term 27-month storage. Results: A slight degradation of the ubiquitous single-copy cellular DNA TOP3 gene was assessed using multiplex real-time PCR (BMRT Human Papillomavirus Genotyping Real Time PCR Kit, Bioperfectus Technologies Co., Ltd., Taizhou, Jiangsu, China) at positive temperatures (+4 °C and +25 °C) but not at a frozen temperature (−30 °C) after 27 months of storage. Nevertheless, HPV DNA preservation was sufficient at the three storage temperatures to detect and quantify HPV DNA, with a similar rate of HPV detection, a similar level of cumulative HPV viral loads, high sensitivity and specificity, and perfect concordance in HPV genotype detection after the long period of 27 months of storage. Finally, the conservation of genital samples for a prolonged period in the Cyt-All® medium, even at room temperature, allows for the detection and quantification of any HPV and HR-HPV with high accuracy. Conclusions: The combination of veil-based self-sampling of female genital secretions and their elution and conservation in UTM may be used in the field to carry out longitudinal molecular epidemiology surveys of circulating HPV.