epididymis and seminal vesicles. other causes of unusual semen colour include sexually transmitted infections such as gonorrhea and chlamydia, genital surgery and injury to the male sex organs. fructose level fructose level in the semen may be analysed to determine the amount of energy available to the semen for moving. who specifies a normal level of 13 μmol per sample. absence of fructose may indicate a problem with the seminal vesicles. ph according to one lab test manual normal ph range is 7.2–8.2; who criteria specify normal as 7.2–7.8. acidic ejaculate (lower ph value) may indicate one or both of the seminal vesicles are blocked. a basic ejaculate (higher ph value) may indicate an infection. a ph value outside of the normal range is harmful to sperm and can affect their ability to penetrate the egg. the final ph results from balance between ph values of accessory glands secretions, alkaline seminal vesicular secretion and acidic prostatic secretions. liquefaction the liquefaction is the process when the gel formed by proteins from the seminal vesicles and the prostate is broken up and the semen becomes more liquid. it normally takes between 30 minutes and 1 hour for the sample to change from a thick gel into a liquid. in the nice guidelines, a liquefaction time within 60 minutes is regarded as within normal ranges. viscosity semen viscosity can be estimated by gently aspirating the sample into a wide-bore plastic disposable pipette, allowing the semen to drop by gravity and observing the length of any thread. high viscosity can interfere with determination of sperm motility, sperm concentration and other analysis. mot mot is a measure of how many million sperm cells per ml are highly motile,that is, approximately of grade a (>25 micrometer per 5 sek. at room temperature) and grade b (>25 micrometer per 25 sek. at room temperature). thus, it is a combination of sperm count and motility. with a straw or a vial volume of 0.5 milliliter, the general guideline is that, for intracervical insemination (ici), straws or vials making a total of 20 million motile spermatozoa in total is recommended. this is equal to 8 straws or vials 0.5 ml with mot5, or 2 straws or vials of mot20. for intrauterine insemination (iui), 1–2 mot5 straws or vials is regarded sufficient. in who terms, it is thus recommended to use approximately 20 million grade a+b sperm in ici, and 2 million grade a+b in iui. dna damage dna damage in sperm cells that is related to infertility can be probed by analysis of dna susceptibility to denaturation in response to heat or acid treatment and/or by detection of dna fragmentation revealed by the presence of double-strand breaks detected by the tunel assay. other techniques performed in order to measure the dna fragmentation are: scd (sperm chromatin dispersion test), isnt (in situ nick translation), scsa (sperm chromatin structural assay) and comet assay. total motile spermatozoa total motile spermatozoa (tms) or total motile sperm count (tmsc) is a combination of sperm count, motility and volume, measuring how many million sperm cells in an entire ejaculate are motile. use of approximately 20 million sperm of motility grade c or d in ici, and 5 million ones in iui may be an approximate recommendation. others the sample may also be tested for white blood cells. a high level of white blood cells in semen is called leucospermia and may indicate an infection. cutoffs may vary, but an example cutoff is over 1 million white blood cells per milliliter of semen. abnormalities aspermia: absence of semen azoospermia: absence of sperm hypospermia: low semen volume hyperspermia: high semen volume oligozoospermia: very low sperm count asthenozoospermia: poor sperm motility teratozoospermia: sperm carry more morphological defects than usual necrozoospermia: all sperm in the ejaculate are dead leucospermia: a high level of white blood cells in semen factors that influence results apart from the semen quality itself, there are various methodological factors that may influence the results, giving rise to inter-method variation. compared to samples obtained from masturbation, semen samples from collection condoms have higher total sperm counts, sperm motility, and percentage of sperm with normal morphology . for this reason, they are believed to give more accurate results when used for semen analysis. if the results from a man's first sample are subfertile, they must be verified with at least two more analyses. at least two to four weeks must be allowed between each analysis. results for a single man may have a large amount of natural variation over time, meaning a single sample may not be representative of a man's average semen characteristics. in addition, sperm physiologist joanna ellington believes that the stress of producing an ejaculate sample for examination, often in an unfamiliar setting and without any lubrication (most lubricants are somewhat harmful to sperm), may explain why men's first samples often show poor results while later samples show normal results. a man may prefer to produce his sample at home rather than at the clinic. the site of semen collection does not affect the results of a semen analysis.. if produced at home the sample should be kept as close to body temperature as possible as exposure to cold or warm conditions can affect sperm motility measurement methods pre-weighted container for semen analysis volume can be determined by measuring the weight of the sample container, knowing the mass of the empty container. sperm count and morphology can be calculated by microscopy. sperm count can also be estimated by kits that measure the amount of a sperm-associated protein, and are suitable for home use. computer assisted semen analysis (casa) is a catch-all phrase for automatic or semi-automatic semen analysis techniques. most systems are based on image analysis, but alternative methods exist such as tracking cell movement on a digitizing tablet. computer-assisted techniques are most-often used for the assessment of sperm concentration and mobility characteristics, such as velocity and linear velocity. nowadays, there are casa systems, based on image analysis and using new techniques, with near perfect results, and doing full analysis in a few seconds. with some techniques, sperm concentration and motility measurements are at least as reliable as current manual methods. raman spectroscopy has made progress in its ability to perform characterization, identification and localization of sperm nuclear dna damage.