Description
Clinical relevance
Newborn screening aims to detect congenital metabolic disorders early on before they can cause harm to the organism. Included in these diseases are defects of amino acid metabolism such as phenylketonuria (PKU) and maple syrup urine disease (MSUD), defects of fatty acid metabolism and organic acidurias (isovaleric acidemia). If these diseases are not diagnosed, the metabolic disorders can already lead to severe irreversible harm to the newborns within their first few days of life.
Mass spectrometry is the method of choice for diagnostic testing: it enables to check for a broad range of metabolic defects in a single run. An HPLC column is not required due to the high selectivity of LC-MS/MS. This makes it possible to achieve a very precise quantification in a very short analysis time of less than 2 minutes.
Product advantages
- Simple SUAC determination with upgrade set
- Screening for many metabolic disorders in a single run such as PKU (Phenylketonuria), MSUD (Maple Syrup Urine Disease) and tyrosinemia type I
- Each analyte safeguarded by its own internal standard
This Chromsystems assay allows the fast and reliable determination of amino acids, acylcarnitines and succinylacetone from dried blood spot samples as part of the newborn screening for amino acid and fatty acid metabolic disorders using tandem mass spectrometry. Sample preparation is based on effective extraction of the analytes from the blood spot without any further sample preparation steps required. The use of stable isotope labelled internal standards for calibration and measurement ensures reliable and precise quantification of the analytes.
For the analysis of succinylacetone an upgrade set is available (order no. 57111).
Here's an overview of all our newborn screening assays.
Technical Data
Method of Analysis
Number of Tests
Parameter
Analysis Time
Limit of quantification
Amino acids with SUAC: 0.5-12 µmol/l
(Acyl-)carnitines: 0.01-1.9 µmol/l
Linearity
Amino acids with SUAC: 120-7000 µmol/l
(Acyl-)carnitines: 15-400 µmol/l
Recovery
Intraassay
Amino acids with SUAC: CV = 2-10 %
(Acyl-)carnitines: CV = 3-8 %
Interassay
Amino acids with SUAC: CV = 4.3-10 %
(Acyl-)carnitines: CV = 4.3-10.8 %
Cutoff thresholds
Amino acids | 30–1090 µmol/l |
Free carnitine | ca. 55 µmol/l |
Acylcarnitines | 0.2–73 µmol/l |
SUAC | 1.2 µmol/l |
Information
Mass transitions of analytes and internal standards
Amino acids and SUAC | MRM |
Alanine | 90 > 44 |
Alanine-D4 | 94 > 48 |
Arginine | 175 > 70 |
Arginine-D7 | 182 > 77 |
Aspartic acid | 134 > 116 |
Aspartic acid-D3 | 137 > 119 |
Citrulline | 176 > 113 |
Citrulline-D2 | 178 > 115 |
Glutamic acid | 148 > 130 |
Glutamic acid-D5 | 153 > 135 |
Glycine | 76 > 30 |
Glycine-13C2-15N | 79 > 32 |
Leucine | 132 > 86 |
Leucine-D3 | 135 > 89 |
Methionine | 150 > 133 |
Methionine-D3 | 153 > 136 |
Ornithine | 133 > 70 |
Ornithine-D6 | 139 > 76 |
Phenylalanine | 166 > 120 |
Phenylalanine-D5 | 171 > 125 |
Proline | 116 > 70 |
Proline-D7 | 123 > 77 |
Tyrosine | 182 > 136 |
Tyrosine-D4 | 186 > 140 |
Valine | 118 > 72 |
Valine-D8 | 126 > 80 |
SUAC | 155 > 137 |
SUAC-13C5 | 160 > 142 |
Acylcarnitines and free carnitine | MRM |
Carnitine | 162 >85 |
Carnitine-D9 | 171 > 85 |
C2-Carnitine | 204 > 85 |
C2-Carnitine-D3 | 207 > 85 |
C3-Carnitine | 218 > 85 |
C3-Carnitine-D3 | 221 > 85 |
C4-Carnitine | 232 > 85 |
C4-Carnitine-D3 | 235 > 85 |
C5-Carnitine | 246 > 85 |
C5-Carnitine-D9 | 255 > 85 |
C5DC-Carnitine | 276 > 85 |
C5DC-Carnitine-D6 | 282 > 85 |
C6-Carnitine | 260 > 85 |
C6-Carnitine-D3 | 263 > 85 |
C8-Carnitine | 288 > 85 |
C8-Carnitine-D3 | 291 > 85 |
C10-Carnitine | 316 > 85 |
C10-Carnitine-D3 | 319 > 85 |
C12-Carnitine | 344 > 85 |
C12-Carnitine-D3 | 347 > 85 |
C14-Carnitine | 428 > 85 |
C14-Carnitine-D3 | 375 > 85 |
C16-Carnitine | 400 > 85 |
C16-Carnitine-D3 | 403 > 85 |
C18-Carnitine | 428 > 85 |
C18-Carnitine-D3 | 431 > 85 |
Flow rate
Specimen
Pre-analytic Treatment
Specimen collection: whole blood from the heel of the newborn taken onto a filter card. Collection between 24th and 72nd hour of life depending on individual national guideline.
Stability: storage at low humidity (< 30 %) and ambient temperature is sufficient if analysis is performed within 24 to 48 hours. For longer storage deep-freeze samples with humidity excluded below -18 °C.
Sample Preparation
- Punch out 3.2 mm blood spots from the filter cards into a 96 Well Plate.
- Add 100 μl Internal Standard and agitate for 20 min.
- Transfer supernatant into a new 96 Well Plate (or with 57000/F centrifuge for 2 min).
- Inject up to 10 μl into the LC-MS/MS system.
In the sample preparation for the analysis of succinylacetone the following additional steps have to be performed before injection: Add Internal Standard and Extraction Buffer, agitate 30 min, combine extracts (pipette), incubate 20 min.
For details please refer to the instruction manual.
Injection Volume
Autosampler rinsing solution
MS/MS-Mode
Additional Info
No HPLC column is required.