FAQ1: Can the Fructose test be performed on frozen/thawed semen plasma samples?
Yes it can. It is best to centrifuge the semen sample before freezing the semen plasma at -18°C or below.

FAQ2: Is measurement at alternative wavelengths possible?
It is recommended to measure at 450-492nm, no data on other wavelengths is available. If an alternative wavelength is applied, investigate the efficiency before implementing it.

FAQ3: Is there a template for the calculations available?
Yes, it can be downloaded from our website in the product page. Alternatively, an Excel-sheet template can be downloaded directly by clicking here.

FAQ4: Calculation of g-forces
The g-force of your centrifuge can be calculated using this formula:
g = 1.118 x r x rpm² or rpm = Square root {g / (1.118 x r)}
r = radius of centrifuge in mm; rpm = rotations per minute / 1000
e.g.1
r = 100 mm rpm = 3000 rotations per minute
g = 1.118 x 100 x 9 = 1006g
e.g.2
r = 100 mm g = 1200g
rpm = SQR {1200 / (1.118 x 100)} = 3.28
= 3280 rotations per minute

Measuring range of the Fructose Test is defined as 0.5-5 mg/ml. If higher concentrations are determined it is advised to repeat the test with diluted sample in FertiCult Flushing medium (FertiPro NV).

FAQ5: Is internal QC testing for the Fructose Test required at the laboratory and is there a method for QC testing that can be performed?
If required by laboratory procedures, an internal QC control may be conducted (e.g. for training of new employees, for each new batch, if there is doubt about the integrity of the reagents). For this, FertiPro would suggest to use the following protocol:

Prepare a seminal plasma QC sample:

1. Create a pool of different patient samples.
2. Centrifuge semen at 3000g for 20 minutes to remove spermatozoa, and keep the seminal plasma for further tests.
3. Mix seminal plasma thoroughly and make aliquots.
4. Label an appropriate number of test tubes (include QC batch ID and date).
5. Fill the first 5 test tubes with 1200 µL of the pooled seminal plasma.
6. Dispense the remaining plasma in 250 µL aliquots into the other tubes.
7. Seal the tubes and store at -20°C until further use (max 12 months).

Determine the fructose concentration of the QC sample:

1. Measure the fructose concentration in 10 replicates on 5 different occasions (following the protocol as described in the IFU of the Fructose Test).
2. Use the 1200 µL aliquots for these measurements.
3. Calculate the 95% confidence interval for the fructose concentration.

QC during routine analyses:

1. Add a QC sample and treat this as a normal sample.
2. The result of the QC sample must fall within the 95% confidence interval of the fructose concentration for the test to be considered valid.