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Pregnancy-Associated Plasma Protein A, Pappalysin 1 (PAPPA) Kit ELISA

Détails pour le produit réf. ABIN996926, Fournisseur: Connectez-vous pour afficher
  • 8430414N03Rik
  • IGFBP-4ase
  • PAG1
  • PAPP-A
  • DIPLA1
  • PAPA
  • PAPPA1
  • Pappa
Kits with alternative reactivity to:
Gamme de detection
0-30 μg/mL
Seuil minimal de détection
0 μg/mL
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Type d'échantillon Serum
Specificité 96?%
Sensibilité 0.133 μg/mL
Matériel non inclus 1. A microtiter plate calibrated reader (450 ± 10 nm) (e. g. the DAI Microtiter Plate Reader).
2. Calibrated variable precision micropipettes.
3. Absorbent paper.
4. Distilled or Deionized water
5. Timer (60 min. range).
6. Semi logarithmic graph paper or software for data reduction.
Autre désignation PAPP-A (PAPPA ELISA Kit Extrait)
Sujet PAPP-A is a protein produced by the developing placenta. Its concentration in the maternal blood increases rapidly after the 7th week of pregnancy. The measurement of PAPP-A in the first trimester of pregnancy has been reported as a useful marker in antenatal screening for Down Syndrome and other fetal aneuploidies. Reduced PAPP-A values in combination with maternal age, the measurement of free beta-HCG and the ultrasonic determination of nuchal translucency (NT) in pregnancy weeks 11 to 14 may detect up to 90 % of pregnancies with Down syndrome. The DAI PAPP-A ELISA EIA-2397 may be used for the risk assessment of Down´s syndrome (trisomy 21) in the first trimester of pregnancy. For the risk assessment of trisomy 21 and other fetal aneuploidies PAPP-A should always be measured in combination with other analytes (for example free beta-HCG and NT, see above) and a special software for the risk assessment of trisomy 21. According to the IVD Directive (98/79/EC) both software and kits for the additional analytes must be suitable for trisomy 21 screening and CE-certified by a notified body, indicated by the identification number of the notified body on the CE-mark on software and kits.

Quality Control:
Good laboratory practice requires that controls be run with each calibration curve. A statistically significant number of controls should be assayed - establish mean values and acceptable ranges - assure proper performance. It is recommended - use control samples according - state and federal regulations. The use of control samples is advised - assure the day - day validity of results. Use controls at both normal and pathological levels. The controls and the corresponding results of the QC-Laboratory are stated in the QC certificate added - the kit. The values and ranges stated on the QC sheet always refer - the current kit lot and should be used for direct comparison of the results. It is also recommended - make use of national or international Quality Assessment programs in order - ensure the accuracy of the results. Employ appropriate statistical methods for analysing control values and trends. If the results of the assay do not fit - the established acceptable ranges of control materials patient results should be considered invalid. Diagnostic Automation/Cortez Diagnostics, Inc. 23961 Craftsman Road, Suite D/E/F, Calabasas, CA 91302 USA Phone: SIS.591.3030 Fax S1S.591.S3S3 Email: Website: In this case, please check the following technical areas: Pipetting and timing devices, photometer, expiration dates of reagents, storage and incubation conditions, aspiration and washing methods. C After checking the above mentioned items without finding any error contact your distributor or DAI directly.
Limitations of procedure: Reliable and reproducible results will be obtained when the assay procedure is performed with a complete understanding of the package insert instruction and with adherence - good laboratory practice. Any improper handling of samples or modification of this test might influence the results. Interfering Substances Haemoglobin (up - 4 mg/mL), Bilirubin (up - 0.5 mg/mL) and Triglyceride (up - 30 mg/mL) have no influence on the assay results. Drug Interferences Until today no substances (drugs) are known - us, which have an influence - the measurement of PAPP-A in a sample. High-Dose-Hook Effect No hook effect was observed in this test up - 300 ?g/mL of PAPP-A.

Legal Aspects
1. Reliability of Results The test must be performed exactly as per the manufacturer's instructions for use. Moreover the user must strictly adhere - the rules of GLP (Good Laboratory Practice) or other applicable national standards and/or laws. This is especially relevant for the use of control reagents. It is important - always include, within the test procedure, a sufficient number of controls for validating the accuracy and precision of the test. The test results are valid only if all controls are within the specified ranges and if all other test parameters are also within the given assay specifications. In case of any doubt or concern please contact DAI.
2. Therapeutic Consequences Therapeutic consequences should never be based on laboratory results alone even if all test results are in agreement with the items as stated under point 11.1. Any laboratory result is only a part of the total clinical picture of a patient. Only in cases where the laboratory results are in acceptable agreement with the overall clinical picture of the patient should therapeutic consequences be derived. The test result itself should never be the sole determinant for deriving any therapeutic consequences.
3. Liability Any modification of the test kit and/or exchange or mixture of any components of different lots from one test kit - another could negatively affect the intended results and validity of the overall test. Such modification and/or exchanges invalidate any claim for replacement. Claims submitted due - customer misinterpretation of laboratory results subject - point 11.2. are also invalid. Regardless, in the event of any claim, the manufacturer's liability is not - exceed the value of the test kit. Any damage caused - the test kit during transportation is not subject - the liability of the manufacturer.

Volume d'échantillon 50 μL
Durée du test 1 - 2 h
Préparation des réactifs

Allow all reagents and required number of strips to reach room temperature prior to Standards Reconstitute the lyophilized contents of the standard vial with 150 μL Aqua dest.
Note: The reconstituted standards are stable for 2months at 2-8 °C. Control Reconstitute the lyophilized content with 150 μL Aqua dest and let stand for 10 minutes in minimum. Mix the control several times before use. Note: The reconstituted control is stable for 2 months at 2-8 °C Wash Solution Add deionized water to the 40X concentrated Wash Solution. Dilute 30 mL of concentrated Wash Solution with 1170 mL deionized water to a final volume of 1200 mL. The diluted Wash Solution is stable for 2 weeks at room temperature. Enzyme Conjugate 30 minutes before use dilute 1.0 mL of concentrated Enzyme Conjugate with 10 mL Conjugate Diluent. Note: The Enzyme Conjugate has to be prepared fresh 30 min. before use and cannot be stored longer than 24 hours. If more than one test run is performed, dilute only the quantity required for each test run.

Préparation de l'échantillon

Serum or plasma (EDTA-, heparin- or citrate plasma) can be used in this assay. Do not use haemolytic, icteric or lipaemic specimens. Please note: Samples containing sodium azide should not be used in the assay. 1. Specimen Collection Serum: Collect blood by venipuncture (e.g. Sarstedt Monovette # 02.1388.001), allow to clot, and separate serum by centrifugation at room temperature. Do not centrifuge before complete clotting has occurred. Patients receiving anticoagulant therapy may require increased clotting time. Plasma: Whole blood should be collected into centrifuge tubes containing anti coagulant and centrifuged immediately after collection. (E.g. for EDTA plasma Sarstedt Monovette - red cap - # 02.166.001, for Heparin plasma Sarstedt Monovette - orange cap - # 02.165.001, for Citrate plasma Sarstedt Monovette - green cap - # 02.167.001.) 2 Specimen Storage Specimens should be capped and may be stored for up to 5 days at 2-8 °C prior to assaying. If EDTA plasma is stored at 2-8 °C, it must be assayed within 48 hours. S pec ime n s held for a lo nge r tim e (up to tw o m onth s ) sh ould be froz en only o n ce at -20 °C prior to assay. Thawed samples should be inverted several times prior to testing. 3 Specimen Dilution If in an initial assay, a specimen is found to contain more than the highest standard, the specimens can be diluted with Standard 0 .

Procédure de l'essai
  1. General Remarks
    1. All reagents and specimens must be allowed to come to room temperature before use. All reagents must be mixed without foaming.
    2. Once the test has been started, all steps should be completed without interruption.
    3. Use new disposal plastic pipette tips for each standard, control or sample in order to avoid cross contamination.
    4. Absorbance is a function of the incubation time and temperature. Before starting the assay, it is recommended that all reagents are ready, caps removed, all needed wells
    5. secured in holder, etc. This will ensure equal elapsed time for each pipetting step
    6. without interruption.
    7. As a general rule the enzymatic reaction is linearly proportional to time and temperature.
Calcul des résultats
  1. Calculate the average absorbance values for each set of standards, controls and patient samples.

    2. Construct a standard curve by plotting the mean absorbance obtained from each standard against its concentration with absorbance value on the vertical(Y) axis and concentration on the horizontal (X) axis.

    3. Using the mean absorbance value for each sample determine the corresponding concentration from the standard curve.
    4. Automated method: The results in the IFU have been calculated automatically using a 4 PL (4 Parameter Logistics) curve fit. 4 Parameter Logistics is the preferred method. Other data reduction functions may give slightly different results.
    5. The concentration of the samples can be read directly from this standard curve. Samples with concentrations higher than that of the highest standard have to be further diluted. For the calculation of the concentrations this dilution factor has to be taken into account. Example of Typical Standard Curve The following data is for demonstration only and cannot be used in place of data generations at the time of assay. Standard Optical Units (450 nm) Standard 0 (0 μg/mL) 0.18 Standard 1 (1 μg/mL) 0.38 Standard 2 (
    2.5 μg/mL) 0.56 Standard 3 (5 μg/mL) 0.83 Standard 4 (15 μg/mL)
    1.44 Standard 5 (30 μg/mL)
    It is strongly recommended that each laboratory should determine its own normal and abnormal values. Pregnant women in the 1st trimester 238 samples of pregnant women in the 1st trimester have been measured with the DAI PAPP-A ELISA. The values are validated in comparison with a Gaussian distribution. Consideration of body weight and day of gestation results in the following regression equation: Median (f) PAPP-A = EXP (-
    2.12268 + 0.06324 gestation day - 0.00979 body weight). Use for Down Syndrome Screening For risk calculation in prenatal screening PAPP-A concentrations are indicated as MOM (multiple of medians, MOM = Measured Concentration (PAPP-A) / Median PAPP-A). In Down syndrome pregnancies the median of MOMs for PAPP-A are increasing during the first trimester and are not distinguishable anymore from normal pregnancies during the second trimester (reference 6, details see table). PAPP-A must therefore be measured in the first trimester of pregnancy (completed weeks 1013). Completed week of pregnancy 10 11 12 13 14-20 Median of MOM in pregnancies with Down Syndrome 0,34 0,42 0,50 0,58 1,11 If the values of the same 238 pregnant women are compared with the gestation day only (body weight not considered) the following weight independent regression equation is found: Data from reference 6 For risk calculation of trisomy 21 not only PAPP-A but also other parameters like free BHCG and nuchal translucency (NT) for the 1st trimester and/or AFP, free Estriol and HCG for the 2nd trimester have to be determined. Median (sst) PAPP-A = EXP (-
    2.705444 + 0.0618725 * gestation day). In the following diagram and table the medians of function (median (f) ) for completed pregnancy weeks 8 to 13 have been calculated for three body weights (50 kg, 65 kg (mean body weight), and 100 kg). For comparison the medians were also determined manually (Median of week) and by using the weight independent regression equation (Median (sst). The use of these parameters for risk calculation of trisomy 21 requires a special software. According to the IVD Directive (98/79/EC) both software and kits for the additional analytes must be suitable for trisomy 21 screening and CE-certified by a notified body, indicated by the identification number of the notified body on the CE-mark on software and kits. The software must allow the calculation of medians from own patient measurements. It is imperative to take into consideration additional factors, e.g. age of the woman, weight, ethnic group and smoker/non-smoker. An underestimation of the gestation age can lead to a falsely high calculated risk (false positive). To reduce this source of error, it is important to determine the gestation age as precisely as possible. Gestation age calculation from the last menstrual cycle inheres a high risk of variation. Sonographic determination of the crown-rump length (CRL) or biparietal diameter (BIP) is recommended for the proper determination of the gestation age. PAPP-A measurement in the course of a prenatal screening determines only a risk for trisomy 2
    1. For proof of trisomy 21 genetic determinations are required. Completed week of gestation day of gestation Median(sst) μg/mL] weight independent Median (f) μg/mL] weight 50 kg Median (f) μg/mL] weight 65 kg Median (f) μg/mL] weight 100 kg Median of week μg/mL] 8 59
    1.5 9 66
    3.0 10 73 6.12 7.42 6.4
    4.55 6.7 11 80 9.43 1
    1.55 10.0 7.08 10.5 12 87 14.55 17.99 15.5 1
    1.03 1
    1.6 13 94 2
    2.43 28.00 24.2 17.17 14.9 Population and laboratory differences may lead to slightly different medians. Each laboratory should therefore determine and continuously update its own medians from its own patient collective. The regression equations and values in the table should be used as a guideline only. The calculation of medians and/or regression functions for the calculation of medians from own patient data bases should be performed with the applied trisomy 21 risk calculation software. Medians determined for the DAI PAPP-A ELISA can not be used with assays of other manufacturers. Medians determined for PAPP-A assays of other manufacturers can not be used with the DAI PAPP-A ELISA

    2. Specificity of Antibodies (Cross Reactivity) The antibody used for the DAI PAPP-A ELISA is specific for human PAPP-A. There is no cross-reactivity to other species. No reaction is seen with normal human plasma.

    3. Analytical
Restrictions For Research Use only
Stock 4 °C
Date de péremption 12-14 months
Reference: Background Wald, Rodeck, Hackshaw et al.: "First and second trimester antenatal screening for Down's syndrome: the results of the Serum, Urine and Ultrasound Screening Study (SURUSS)." dans: Health technology assessment (Winchester, England), Vol. 7, Issue 11, pp. 1-77, 2003 (PubMed).

Bindra, Heath, Liao et al.: "One-stop clinic for assessment of risk for trisomy 21 at 11-14 weeks: a prospective study of 15 030 pregnancies." dans: Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, Vol. 20, Issue 3, pp. 219-25, 2002 (PubMed).

"Abstracts of the 12th Fetal Cell Workshop. Prague, Czech Republic, May 12-13, 2001." dans: Fetal diagnosis and therapy, Vol. 16, Issue 6, pp. 437-64, 2002 (PubMed).

Spencer, Souter, Tul et al.: "A screening program for trisomy 21 at 10-14 weeks using fetal nuchal translucency, maternal serum free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A." dans: Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, Vol. 13, Issue 4, pp. 231-7, 1999 (PubMed).

Qin, Christiansen, Oxvig et al.: "Double-monoclonal immunofluorometric assays for pregnancy-associated plasma protein A/proeosinophil major basic protein (PAPP-A/proMBP) complex in first-trimester maternal serum screening for Down ..." dans: Clinical chemistry, Vol. 43, Issue 12, pp. 2323-32, 1998 (PubMed).