RNAlater® Tissue Collection: RNA Stabilization Solution is an aqueous tissue storage reagent that protects RNA within intact, unfrozen tissue and cell samples. RNAlater® Solution was designed to eliminate the need to process samples as soon as they are dissected. This is particularly important when it is not possible to immediately freeze or process samples and an effective reagent is required to stabilize RNA expression profiles within samples.
We have been sharing interesting ways that customers use RNAlater Solution in the TechNotes newsletter for several years. Here, we describe its successful use by Dr. Kosel et al. in storing cervical samples in preparation for human papilloma virus (HPV) nucleic acid analysis.
Kosel S, Burggraf S, Engelhardt W, Olgemoller B (2007) Increased levels of HPV16 E6*I transcripts in high-grade cervical cytology and histology (CIN II+) detected by rapid real-time RT-PCR amplification. Cytopathology 18(5): 290–299.
Cervical dysplasia describes the appearance of abnormal cells on the surface of the cervix and may be classified as mild, moderate, or severe. Cervical dysplasia may regress to normal cytology or progress to cervical carcinoma. It is therefore useful to have diagnostic tools to aid in the decision whether therapeutic conization (the excision of a cone of cervical tissue) or ablation (destruction of abnormal surface cells using a laser beam) is required.
Human papilloma virus (HPV) is one of the most common causes of sexually transmitted infection in the world. Approximately 5.5 million new cases of sexually transmitted HPV infections are reported every year. HPV infection causes genital warts, and it also has been linked to infertility. HPVs, most commonly the HPV16 genotype, are also the causative agents of the majority of cases of cervical dysplasia and invasive cervical carcinoma.
The study by Dr. Kosel and colleagues analyzed data from 301 HPV16-positive cervical samples. Cervical scrape samples were prepped for cytological examination and, in parallel, cells were transferred to 1 mL of RNAlater® Tissue Collection: RNA Stabilization Solution. Samples in RNAlater Solution were stored at ambient temperature until subsequent isolation of RNA and DNA. Next, the researchers used real-time PCR (or real-time RT-PCR) to quantitate HPV16 DNA and HPV16 E6*1 RNA levels relative to endogenous controls. These virus-specific DNA and RNA levels were correlated with either histological diagnoses or cytological follow-up, depending on which data were available.
RNAlater Solution facilitated the collection of patient samples, so that the researchers could isolate intact RNA and DNA for real-time PCR analysis. The study concluded that quantitation of HPV16 E6*I mRNA could be helpful in managing follow-up and treatment in a subset of HPV16 positive women.