Related Experiment Video
Updated: Jan 27, 2026

A Yeast 2-Hybrid Screen in Batch to Compare Protein Interactions
Published on: June 6, 2018
Clinical Performance of SurePath™ Preservative Compared to PreservCyt® with Cobas® and Hybrid Capture® 2 HPV Tests in
Background:
Until recently, no HPV test had been US FDA-approved for SurePath preservative. Clinical performance remains incompletely understood. The clinical performances of the Cobas HPV Test (Cobas) and Hybrid Capture 2 High-Risk HPV DNA Test (HC2) with PreservCyt and SurePath preservatives were compared.
Methods:
Cervical cytology samples were collected in both preservatives in random order from women age 21+ (n = 244) referred for colposcopy. Before cytology processing and pelleting, SurePath samples were tested by the Cobas test with and without buffered SDS heat pretreatment. SurePath pellets were tested by the HC2 test and by the Cobas test (with pretreatment). Performance characteristics were calculated in relation to cases of cervical in-traepithelial neoplasia grade 2 or higher (CIN2+) as the clinical target outcome. All HPV-positive samples were also genotyped with the Linear Array test.
Results:
CIN2+ was detected in 42 patients (17.2%). For both HPV tests, there was a trend towards higher positivity and sensitivity for SurePath compared to PreservCyt preservative. The Cobas test had higher sensitivity than HC2 and the HC2 test had higher specificity than Cobas. Pretreated SurePath samples produced results similar to untreated ones, despite a two-fold dilution during pretreatment [sensitivity %: 95.1 (82.2 - 99.2) vs. 94.3 (79.5 - 99.0); specificity %: 33.0 (26.6 - 40.1) vs. 33.0 (26.4 - 40.3)].
Conclusions:
There was good agreement between the preservatives and HPV tests in detecting HPV and between the Cobas and Linear Array tests for genotyping HR-HPV. These trends were not statistically significant due to the limited number of CIN2+ cases. However, these data may help in evaluations of preservative selection for colposcopy samples. Pre-treatment for Cobas testing eliminated invalid results due to clots. The Cobas test has been FDA-approved for use with heat pretreated SurePath samples.
Related Concept Videos
Testing a Claim about Mean: Known Population SD
Estimating a population mean requires the samples to be distributed normally. The data should be collected from the randomly selected samples having no sampling bias. The sample size needed to be higher than 30, and most importantly, the population standard deviation should be already known.
In most realistic situations, the population standard deviation is often unknown, but in rare circumstances, when it...
Testing a Claim about Population Proportion
There are two methods of testing a claim about a population proportion: (1) Using the sample proportion from the data where a binomial distribution is approximated to the normal distribution and (2) Using the binomial probabilities calculated from the data.
The first method uses normal distribution as an approximation to the binomial distribution. The requirements are as follows: sample size is large...
Testing a Claim about Mean: Unknown Population SD
Estimating a population mean requires the samples to be approximately normally distributed. The data should be collected from the randomly selected samples having no sampling bias. There is no specific requirement for sample size. But if the sample size is less than 30, and we don't know the population standard deviation, a different approach is used;...
Hybrid Zones
Pericarditis II: Clinical Features and Diagnostic Tests
Atherosclerosis II: Clinical Manifestations and Diagnostic Tests

