Frequently asked questions and answers

I can­not log on!

Access to the QuaDeGA por­tal is via the web address

To gain entry to the por­tal a “Cen­ter ID” and “pass­word” are required, both of which can be found on the let­ter accom­pa­ny­ing the test samples.

The “Cen­ter ID” is your participant’s num­ber minus the “TN” pre­fix. So for lab­o­ra­tory “TN-200” their Cen­ter ID is “200”.

Your pass­word is in the con­fir­ma­tion let­ter you received after reg­is­tra­tion and in the let­ter accom­pa­ny­ing each dis­tri­b­u­tion .

Please note: the pass­word con­tains both upper and lower case let­ters which must be entered accord­ingly. Once issued, the pass­word can­not be changed.

When I try to log in I get an error message:

Please check whether your Cen­ter ID and pass­word are entered cor­rectly. In par­tic­u­lar keep in mind that the pass­word con­tains both upper and lower case let­ters and must be entered as such. If the prob­lem per­sists, please inform us and we will try and resolve the issue as quickly as possible.

I have not ordered sam­ples. Why have I received them?

Once you reg­is­ter with QuaDeGA, test mate­r­ial is auto­mat­i­cally sent to you each spring and autumn. The pre­cise dates of future rounds are listed on the QuaDeGA home­page and a few weeks prior to the sam­ples being deliv­ered, an email is sent inform­ing you of the upcom­ing test.

We would like to remind you that par­tic­i­pa­tion in the exter­nal qual­ity con­trol scheme is required by the guide­lines of the Ger­man Fed­eral Med­ical Board (RiLiBÄK), how­ever should you wish to with­draw from QuaDeGA, please refer to the fol­low­ing section.

We did not refrig­er­ate the sam­ple prior to analy­sis. Are they still usable?

The sam­ples pro­vided by QuaDeGA are processed prior to deliv­ery to ensure they arrive in the best pos­si­ble con­di­tion. Although refrig­er­a­tion upon arrival is rec­om­mended, our pro­cess­ing is such that bar­ring unfore­see­able cir­cum­stances, sam­ples kept at room tem­per­a­ture should not be unduly affected.

I can­not view the films for sperm motil­ity eval­u­a­tion. The com­puter does not rec­og­nize the film file.

View­ing the videos requires any of the media play­ers pro­vided by the most com­monly used browsers (e.g. Mozilla Fire­fox, Google Chrome or Inter­net Explorer). These play­ers are freely avail­able and eas­ily down­load­able. The choice of which player to use depends upon which you pre­fer and what is pro­vided by your browser (please refer to the help sec­tion of your browser of choice for more infor­ma­tion). What must be remem­bered is that the play­ers need to be reg­u­larly updated for opti­mal performance.

Do I need spe­cial mate­r­ial for car­ry­ing out the qual­ity control?

The qual­ity con­trol trial is intended to over­see the meth­ods by which you rou­tinely per­form semen analy­sis. It is there­fore impor­tant that you use the same mate­ri­als and meth­ods for the QuaDeGA sam­ples as you do for your patient samples.

We rec­om­mend that all analy­ses be per­formed accord­ing to the WHO guide­lines. These are listed in the cur­rent WHO man­ual, a copy of which can be down­loaded from the WHO web­site (for details please refer to the sec­tion above)

Amongst the more impor­tant rec­om­men­da­tions we would like to high­light that:

  • Pre-dilution for mea­sur­ing sperm con­cen­tra­tion should be per­formed using only WHO rec­om­mended diluents
  • The Neubauer improved count­ing cham­ber should be used.
  • Papan­i­co­laou or Shorr stains should be employed for mor­phol­ogy assessment
  • Of the rapid stain­ing pro­ce­dures the most suit­able is Diff-Quik.

We do not have a lab­o­ra­tory mixer (Vor­tex). Can we work with­out such equipment?

In an emer­gency, sam­ples can be mixed with­out a Vor­tex, by shak­ing them vig­or­ously by hand. This, how­ever, is not ideal. As the con­sis­tency of patient sam­ples varies sub­stan­tially, some of which may require inten­sive mix­ing, the pur­chase of a shaker/mixer is strongly recommended.

Can I use a white-blood-cell pipette?

The quan­tity of test mate­r­ial pro­vided is too small for an accu­rate aliquot to be deliv­ered using a white-blood-cell pipette. As such they should not be used.

For QuaDeGA’s tri­als, as for daily use, we rec­om­mend the method of aliquot­ing and deter­mi­na­tion of sperm con­cen­tra­tion detailed in the WHO guide­lines. For more details please refer to the lat­est WHO man­ual (see next section)

For mor­phol­ogy eval­u­a­tion, are the deliv­ered slides fixed?

The sam­ples pro­vided by QuaDeGA are processed so that they are in the best pos­si­ble con­di­tion when deliv­ered to you. To main­tain the rigour of the eval­u­a­tion, they should be treated as if they were native sam­ples pro­vided by two patients attend­ing your lab­o­ra­tory. Con­se­quently if it is your rou­tine pro­ce­dure to fix sam­ples prior to stain­ing for the assess­ment of sperm mor­phol­ogy, then they should be treated the same way.

Do I have to dilute the sam­ples for mea­sur­ing concentration?

The pur­pose of QuaDeGA is to show how the assess­ment obtained by a lab­o­ra­tory using its rou­tine pro­ce­dures com­pares with those of spe­cific ref­er­ence lab­o­ra­to­ries and those of the entire cohort of par­tic­i­pants. As such the trial sam­ples should be treated exactly as the sam­ples col­lected from patients attend­ing your lab­o­ra­tory. If it is rou­tine for you to pre-dilute sam­ples prior to count­ing then do the same for the QuaDeGA samples.

How can I obtain the WHO lab­o­ra­tory manual?

The man­ual is avail­able elec­tron­i­cally and can be freely down­loaded from the WHO website:

or you can order it: ISBN 978–3-642–21122-5

I can­not enter my results. The sys­tem does not store the data. Why?

The most com­mon causes for this prob­lem are:

Data Entry. Each result can be entered only as a num­ber (i.e. no unit or per­cent­age sign) with a max­i­mum space allow­ing for a pre­ci­sion of two dec­i­mal places (i.e. two spaces after the decimal point). Con­se­quently, only num­bers should be entered that have been rounded off to the sec­ond decimal.

Method Entry: For the result to be acceptable the method by which it was obtained must be indicated. If the method used is not amongst those listed, then the descriptor “other” should be chosen from the pulldown menu.

Not all fields have been com­pleted: If you choose not to par­tic­i­pate in the assess­ment of one (or more) of the test para­me­ters, please remove the check mark (X) from the box (on the right of the screen) which is next to the entry win­dow of the respec­tive parameter(s).

How do I know that the data has been successfully uploaded onto the inter­net plat­form? Why is there no con­fir­ma­tion email?

The suc­cess­ful entry of your data will be fol­lowed by the mes­sage “Data stored”. If you are uncer­tain as to whether the data was suc­cess­fully uploaded, open the form again and your results should appear as entered. If this is not the case, enter the infor­ma­tion again, tak­ing care that all the fields are com­pleted and that no error mes­sages appear. Should the data still not upload, con­tact us and we will do our best to rec­tify the problem.

How are the tar­get val­ues deter­mined?

Tar­get val­ues ​​are derived from a cohort of lab­o­ra­to­ries that strictly adhere to the WHO guide­lines. A “tar­get win­dow” is con­structed cen­tred on the median and extend­ing to the 2.5 to 97.5 per­centile of the results for each para­me­ter obtained by these “ref­er­ence” lab­o­ra­to­ries. This tar­get win­dow is rep­re­sented as a rec­tan­gu­lar box in the results graph and numer­i­cally ​​in the sum­mary table.

How is the graph to be inter­preted?
The graph rep­re­sents the results in the form of a Youden plot with the X axis cor­re­spond­ing to the results of sam­ple A and the Y axis those of sam­ple B. Thus, the point at which the two meet is a graph­i­cal rep­re­sen­ta­tion of both results obtained by a lab­o­ra­tory for that par­tic­u­lar para­me­ter. The point rep­re­sent­ing the results of your lab­o­ra­tory is high­lighted in red for ease of iden­ti­fi­ca­tion. The posi­tion of the point, rel­a­tive to all oth­ers and the tar­get win­dow, pro­vides the means of deter­min­ing a laboratory’s per­for­mance. If the point is within the win­dow, then the results for both sam­ples were within the accept­able range. If it is out­side then an error exists (i.e.  above = over­es­ti­ma­tion; below = underestimation).

How are the results transmitted?

Once a trial is com­pleted each laboratory’s results are listed on QuaDeGA’s inter­net por­tal ( and can be accessed as per the nor­mal logging-in pro­ce­dure. As con­fi­den­tial­ity and anonymity of our par­tic­i­pants is of utmost impor­tance, other than the admin­is­tra­tors of the pro­gram, the results of each lab­o­ra­tory are only acces­si­ble to the actual participant.

Upon the con­clu­sion of each QuaDeGA run, a cer­tifi­cate and record of your par­tic­i­pa­tion in the pro­gram will be sent by mail.

I no longer wish to par­tic­i­pate in the QuaDeGA qual­ity con­trol scheme. What must I do?

To ter­mi­nate your par­tic­i­pa­tion in QuaDeGA all that is nec­es­sary is for a brief, signed let­ter stat­ing your wish to dis­con­tinue your involve­ment in the pro­gram to reach us two weeks prior to the begin­ning of the next trial. Please note if your inten­tion to with­draw does not reach us prior to the com­mence­ment of a cycle and the sam­ples have already been sent, then you will be billed for the trial.