Andrology Lab Tour
The andrology lab at the Loma Linda University Center for Fertility and IVF is responsible for male patient sperm analyses and processing for insemination. Unique services include:
(1) a panel of tests to assess male factor infertility
(2) custom testing of the best sperm wash method for the intrauterine insemination patient and ICSI patient
(3) the triple morphology checkpoints consisting of strict morphology, acrosome integrity and sperm deformity index to find out the overall health of the sperm in the male patient
The correct type of specimen container for semen collection is important. Unsuitable cups such as those shown in the photo should not be used. The lab provides non-toxic specimen cups for our patients. This ensures that the sperm testing is accurate or that the processed sperm can be used for insemination.
One of the sperm tests performed is to check for antisperm antibodies on the sperm surface. By using immunobeads, the type of antibody and location is identified, eg. on the sperm head. Intracytoplasmic sperm injection can bypass this form of male infertility.
One of the most important sperm test is to find out the sperm concentration or sperm count. At this lab, this is done using either a hemocytometer or a Makler chamber. The lab participates in quality assurance programs of the College of American Pathologists and the American Association of Bioanalysts to ensure that the sperm counting is accurately performed.
Motility is important for the sperm to reach the egg in the Fallopian tube. In the lab, motility measurements are categorized into 4 groups according to W.H.O. criteria: Rapid progression (type a), slow progression, nonprogression and immotile. The analyses of sperm movement are done using light microscopy or by the Hamilton-Thorn computer-aided sperm analyzer.
Fertile sperm show off a special type of movement called hyperactivation. It resembles wildly spinning tops at fixed positions with no directional movement. Research studies showed that sperm cells activated for fertilization demonstrated this behavior. This type of movement is measured using the lab computer and reported to the physician to assist in diagnosing male factor problems.
The capacity of each sperm to penetrate the egg membrane and unpack the tightly-coiled DNA found in its head can be assessed with the SPA or sperm penetration assay. Inactive thawed hamster eggs are used in this assay. The number of decondensed sperm heads in each egg is counted as shown in this photo on the left (arrows at 2 of the many heads). The DNA in each head is visible as a green circle under fluorescence microscopy shown on the right. Patients with low egg penetration may need sperm injection during IVF to overcome penetration problems.
The percentage of sperm with normal shapes is obtained after a microscopic analysis of color-stained sperm fixed on a glass slide. The photo shows a type A normal shaped sperm as well as some of the deformed sperm. This method is called the Kruger strict normal morphology or Tygerberg method. Infertile men have less than 4 % normal-shaped sperm in their ejaculate. Furthermore, research studies have linked some shape types to sperm pathologies for instance, tapered sperm with the presence of varicoceles.
One method to test for broken DNA (fragmentation) inside the sperm is to use the fluorescent dye acridine orange to paint sperm with normal DNA green and those with broken DNA a bright orange-red color. The photo on the right shows that routine microscopic evaluation cannot show the difference and that the dye is necessary to expose sperm with broken DNA.
Sperm undergo a maturation process to tightly pack the DNA inside the head and incomplete packing leads to infertility. Mature sperm can be distinguished from immature sperm using the acidic aniline blue eosin stain. Immature sperm are stained dark blue in contrast to the red mature sperm. The two colors can be explained by the difference in the type of amino acids found in the mature versus the immature sperm.
The sperm chromatin status test involves using cationic dye staining to detect both DNA fragmentation and chromatin structure abnormalities. The 4 categories of normal and abnormal stained sperm are : (a) normal orthochromatic stained sperm with a light blue nucleus, (b) abnormal metachromatic stained sperm with an over-stained dark purple nucleus, (c) enlarged abnormal sperm with the entire head stained deep purple due to dispersed chromatin from a disrupted nucleus, and (d) necrotic abnormal sperm with a light pink head that lacks DNA. The photo was taken using light microscopy with oil immersion at a magnification of 500 X. The chromatin status results have been correlated to percentages of fertilized eggs and pregnancy after intracytoplasmic sperm injection (ICSI).
Collection of interesting images.
Sperm cells are washed free of seminal plasma by means of either the swim-up, the gradient centrifugation, motility-enhancer or test-yolk buffer method. A simple pre-testing or trial wash helps decide which method is optimal for each patient. The washed sperm is loaded inside an insemination catheter and the sperm released once the catheter is inside the uterus (arrow) as shown in this model.
The lab is equipped to process sperm from asymptomatic patients with viral infections. The sperm cells are washed several times at a quarantined location and used for sperm injection in the IVF treatment cycle. Maximal precautions are taken at each step in the process.
This concludes a quick tour of the Andrology lab testing and processing procedures. If you have questions, please contact us.