SCD TECHNIQUE:

The method is based on SCD (Sperm Chromatin Dispersion) technology (Fernández et al., J. Androl 24: 59-66, 2003; Fertil Steril 84: 833-842, 2005). Spermatozoa from fresh, frozen, or diluted samples are immersed in an inert agarose microgel on a pretreated slide. After, they are subjected to an initial acid treatment that denatures the DNA in those sperm with fragmented DNA. Following this, they are treated with a lysis solution that eliminates most nuclear proteins. After this treatment, spermatozoa with fragmented DNA do not show a halo, and those with intact DNA show large halos around the nucleoid.

Our patent for DNA fragmentation has been widely tested in universities, clinics, and hospitals in over 50 countries. The highly reproducible and reliable technique is based on Halotech's principles: simplicity, speed, and accessibility. To learn more about our solutions, you will have access to results and publications backed by the major scientific journals, which lend credence to the optimal and beneficial use of our kits

DETECTION OF OXIDATIVE STRESS:

The presence of destructive reactive oxygen species (ROS), a concept associated with oxidative stress, results when natural antioxidant defences are incapable of blocking ROS activity. The net result is that cellular damage occurs at different levels. Somatic and germ cell lines appear to be targets of ROS: when they affect germ cell lines, excess oxidative stress has a direct impact on male fertility (Aitken and De Iuliis, 2010).

Several trials are currently in progress, focused on the evaluation of the various levels of ROS and the molecules responsible for producing oxidative stress. However, they are not used very often in clinical andrology laboratories. Oxisperm provides an established, easy, and reliable assay to the clinic to measure possible excesses of anions associated with oxidative stress (O2). This test is based on the nitro blue tetrazolium (NBT) assay, in the form of a reactive gel (RB) in the Oxisperm kit. The NBT assay is based on the ability of water-soluble tetrazolium salt to be converted into a blue formazan crystal due to the action of superoxide anions (Baehner et al., 1976).

In sperm, the products of this reaction adhere to sperm membranes and can be easily visualised in a bright field microscope (Image 1). These crystals produce an increase in the intensity of the colour in the RG (from yellow through to different levels of purple-blue, as seen in the diagram), that can be easily quantified and compared using a colour scale. Alternatively, a colourimeter can be used to measure the absorbance of the wavelengths, which range from 530 nm to 630 nm. The intensity of the colour is closely tied to the level of oxidative stress (an excess of superoxide ions) in the sample (see the colour palette).