A Detailed Guide On Sperm Chromatin Dispersion Assay
Research shows that male infertility is solely responsible for 20% of all infertility cases, and is also a contributing factor in 30-40% of such cases.1 While semen analysis is the fundamental and widely employed test to check male fertility, the conventional evaluations of sperm concentration, motility percentage, and morphology may not be successful in detecting slight abnormalities in sperm DNA.2 Here’s where DNA Fragmentation Index (DFI) can provide the much-needed answers related to the quality of sperm DNA and the genetic causes behind male infertility. In this blog, we shall discuss one of the many techniques used to measure DFI, Sperm Chromatin Dispersion, in detail. Let’s dive right in!
What Is Sperm Chromatin Dispersion Assay?
Sperm DNA can be fragmented or broken into smaller pieces due to varying factors that include internal genetic factors, or external factors like smoking, chemotherapeutics, radiation, heat and more.3 Sperm Chromatin Dispersion (SCD) assay is a test that helps identify and quantify sperm with fragmented DNA.4 This technique is quick, easy, and can be performed without the need for complex laboratory equipments.4 Furthermore, SCD is more sensitive than other processes like the TUNEL assay (method to the level of DNA degradation in dying cells) for detecting DNA damage in men with unexplained infertility.5
How Does Sperm Chromatin Dispersion Work?
The working principle of SCD is quite straightforward. The sperm sample is immersed in agarose gel on a slide.6 Then they are incubated in an acid-unwinding solution. This transforms the DNA breaks into single-stranded DNA. Next, they are added to a lysing solution (a chemical solution that can break bonds between sperm DNA and surrounding proteins) to eliminate nuclear proteins around the DNA.6
Lastly, the spermatozoa are stained and visualised via fluorescence microscopy or bright-field microscopy.6 The sperm cells with normal DNA demonstrate big halos (a circle of light) in the nucleus whereas the ones with fragmented DNA appear with small or no halos steps shown in the image given below.6,7
What Do The Results Of SCD Assay Mean?
Once all the steps of the sperm chromatin dispersion test are completed, the experts calculate the DFI of the sperm sample, i.e. the ratio of sperm with fragmented DNA to those with normal DNA in the sample. DFI above 30% is considered to be abnormal and can also be observed in infertile men with normal semen analysis results.8,9
High DNA fragmentation Index values are also frequently observed in couples who experience frequent abortions.9 Additionally, it may also have adverse effects on the outcomes of artificial reproductive techniques like in-vitro fertilization (IVF) and Intracytoplasmic sperm injection (ICSI).9,11
Parting Thoughts
In conclusion, the sperm chromatin dispersion process is an effective and reliable method for assessing the DNA fragmentation index in men experiencing infertility. SCD is considered to be a valuable tool for diagnosing male infertility and can provide valuable information for clinicians when designing a personalised treatment plan. In case you’re considering delayed parenthood, facing fertility issues, actively trying to conceive, or wish to understand your sperm health, Sperm test can come to your rescue. It includes thorough semen analysis including the analysis of your DNA fragmentation index through the SCD process. This test helps fertility experts offer the best possible chance of conception through sperm cryopreservation for the appropriate duration.
References
+
Related Posts
Related Products
