SpermComet® Test

Introduction

SpermComet® is Examen’s market leading sperm DNA test. SpermComet® is a robust biomarker for male infertility, IVF and ICSI failure and miscarriage.  Independent research has shown that it is the best performing sperm DNA test in terms of sensitivity, specificity and predictive power. SpermComet® is the only sperm DNA test guaranteed for oligozoospermic and testicular samples.

Most sensitive assay for sperm DNA damage

All sperm DNA tests are not equal. Available tests measure different aspects of sperm chromatin damage and as a result have variable levels of diagnostic and prognostic strength (Table 1). SpermComet® is based on a technique known as single cell gel electrophoresis (SCGE). This technique is used extensively in drug toxicity research. Independent research has shown that the SpermComet® is the most sensitive assay for detecting DNA damage (Figure 1 and 2). This is due to several unique features of the assay:

Detects actual DNA damage: SpermComet® detects single- and double-strand DNA fragments present in individual sperm, making it a direct assay of damaged DNA. In contrast, both the SCSA and Halo assays detect faults in the nuclear proteins protecting the DNA. Nuclear protein damage could make the DNA more vulnerable to damage, but it is not a measure of the actual damage to the DNA molecule itself.

Detects total DNA damage: Sperm DNA is up to 6 times more tightly packed than somatic cell DNA. The SpermComet® assay includes a decondensation step which relaxes the DNA exposing DNA strand breaks in the nuclear core. This step is necessary to detect total and not just peripheral DNA damage.

Quantifies amount of DNA damage: Separation of the DNA fragments contained in individual sperm nuclei during electrophoresis allows the amount of DNA fragments to be quantified. In contrast, the other assays only measure either the presence or absence of chromatin or DNA damage.

Best predictor of male infertility

Independent research has shown that the SpermComet® is the best assay for differentiating between fertile and infertile men (Table 2). It has a very high sensitivity and specificity in predicting male infertility. The high sensitivity of the SpermComet® means that it detects a high proportion of true positives i.e. samples likely to achieve a spontaneous pregnancy. The high specificity of the SpermComet® means that it also detects a high proportion of true negatives i.e. samples unlikely to achieve a spontaneous pregnancy.

Best predictor of IVF and ICSI outcomes

Conflicting research results have led to confusion about the relationship between sperm chromatin damage and ART outcomes.  Much of this confusion can be explained by the fact that the type of assay used to measure sperm chromatin damage influences the detection of associations with ART outcomes. Recent independent research has shown that the SpermComet® is the only assay that is predictive of every early ART checkpoint including:

  • Fertilisation rate for IVF
  • Embryo and blastocyst quality
  • Implantation rate
  • Pregnancy rate

In the same research, the TUNEL assay showed no significant correlation with embryo or blastocyst quality and the SCSA assay was not predictive of any ART outcome (Figures 3-5). SpermComet® has been shown to have high sensitivity and moderate specificity in predicting pregnancy following ART (Table 3). The high sensitivity of the SpermComet® means that it detects a high proportion of true positives i.e. samples likely to achieve an ART pregnancy. The moderate specificity of the SpermComet® means that it also detects a good proportion of true negatives i.e. samples unlikely to achieve an ART pregnancy.

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