Novel method for screening for the presence of haemoglobin S in blood (original) (raw)
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Setting Up and Statistical Evaluation of a New Haemoglobin Assay
Clinical Chemistry and Laboratory Medicine, 1995
A new method for the determination of haemoglobin concentration in human whole blood has been devised. The assay takes advantage of the lysis of erythrocytes that occurs when blood penetrates the pores of a microporous membrane by a strong capillary effect. The released haemoglobin reacts with the reagents previously dried on the membrane, diffuses through the pores of the membrane and produces a uniform coloured spot whose reflectance at 556 nm can be evaluated at the side opposite to that of application of the sample. In the experimental conditions used by authors, a linear relationship was obtained when the reciprocal reflectance was plotted against the haemoglobin concentration. Data obtained by the reflectometric method were compared with reference values on the same samples from centralized laboratories. Statistical analysis gave a correlation coefficient of 0.985 and only 4% of all haemoglobin determinations were outside the 95% confidence interval. No interference was observed by haematocrit, erythrocyte count, mean corpuscular volume or mean corpuscular haemoglobin concentration and leukocyte count. This method proved to be useful for rapid, accurate and precise assay of total haemoglobin on both capillary and venous blood.
Role of HPLC (High Performance Liquid Chromatography) as a Tool For Detection of Hemoglobinopathies.
IOSR Journals , 2019
Haemoglobin variants with retention times in the F window (1.00-1.30 min): At least seven haemoglobin variants (four β-and three α-variants) are expected to elute in this window, all in quantities >10 per cent5. However, most of our patients with high Hb in the F window were mostly homozygous β-thalassaemia patients or double heterozygous β thalassaemia/haemoglobinopathy and sickle cell disorder patients . The haplotype of HbS gene that is prevalent in India is the Saudi Arabia/Indian haplotype. This haplotype is associated with higher levels of HbF which reduces the clinical severity of the disease.
… of Chromatography B: …, 1977
Microchromatographic procedures on columns of DEAE-or CM-cellulose are described for the separation of the more common abnormal hemoglobins S and C from other, often uncommon, variants such as J, N, I, K-Woolwich, Hope, D, E, O, and Deer Lodge. Two ...
Effects of hemoglobin C, D, E, and S traits on measurements of HbA1c by six methods
2012
Dear editor Glycated hemoglobin is hemoglobin that has been irreversibly modified by addition of glucose through a non-enzymatic process and provides a weighted average of plasma glucose concentration over the erythrocyte lifespan. HbA 1c is a specific glycated hemoglobin that is modified at the N-terminal valine of the Hb beta chains. HbA 1c therefore provides a useful estimate of mean glycemia in patients with diabetes that has been shown to be directly related to risks for diabetes complications. Treatment goals for HbA 1c have been established, and more recently the test has been recommended for use in diagnosing diabetes (1,2). Therefore, accurate and precise measurement of HbA 1c is extremely important. The most common hemoglobin variants worldwide are HbS, HbE, HbC and HbD traits. Previous studies have shown method-specific analytic interference with HbA 1c results from these heterozygous hemoglobin variants. This study was approved by the University of Utah Institutional Review Board. Whole blood samples from individuals homozygous for HbA (n=42) and heterozygous for HbC, HbD, HbE, or HbS trait (n=23, n=41, n=76, n=40, respectively) were collected in EDTA tubes. Samples were frozen at −70°C in small aliquots and shipped on dry ice to 4 sites for HbA 1c analysis. Hemoglobin variants were identified by inspection of chromatograms obtained with a Bio-Rad Variant analyzer (Bio-Rad Laboratories, Hercules, CA) using the β Thal Short Program; samples with HbF >5% were excluded. Samples with HbA 1c concentrations of 4-12% were included in this study.
Journal of Blood Medicine, 2017
Blood donor hemoglobin (Hb) estimation is an important donation test that is performed prior to blood donation. It serves the dual purpose of protecting the donors' health against anemia and ensuring good quality of blood components, which has an implication on recipients' health. Diverse cutoff criteria have been defined world over depending on population characteristics; however, no testing methodology and sample requirement have been specified for Hb screening. Besides the technique, there are several physiological and methodological factors that affect accuracy and reliability of Hb estimation. These include the anatomical source of blood sample, posture of the donor, timing of sample and several other biological factors. Qualitative copper sulfate gravimetric method has been the archaic time-tested method that is still used in resource-constrained settings. Portable hemoglobinometers are modern quantitative devices that have been further modified to reagent-free cuvettes. Furthermore, noninvasive spectrophotometry was introduced, mitigating pain to blood donor and eliminating risk of infection. Notwithstanding a tremendous evolution in terms of ease of operation, accuracy, mobility, rapidity and cost, a component of inherent variability persists, which may partly be attributed to pre-analytical variables. Hence, blood centers should pay due attention to validation of test methodology, competency of operating staff and regular proficiency testing of the outputs. In this article, we have reviewed various regulatory guidelines, described the variables that affect the measurements and compared the validated technologies for Hb screening of blood donors along with enumeration of their merits and limitations.
Comparison of four chromatographic methods used for measurement of glycated hemoglobin
Revista Romana de Medicina de Laborator, 2016
This parameter’s results accuracy has a special importance in the management of diabetic patients since targets for optimal glycemic control are established using HbA1c values. Several error sources can influence the obtained value, some of them can be counteracted (ex. pipetting errors, storage), and others should be taken into consideration at the interpretation of the result (ex. presence of hemoglobin variants). The aim of this study was to compare four chromatographic methods regarding the costs and the influence of certain error sources on the accuracy of the result. Materials and methods: Samples and controls were analyzed using Variant I, Micromat II and In2it (Bio-Rad) systems, and the BIOMIDI reagent kit for HbA1c measurement. Results: Positive correlation could be observed comparing the results obtained using different methods, except the patients presenting elevated HbF. Pipetting errors modify the results up to 5% in case of Variant I, and up to 10% in case of Micromat ...
Haemoglobin Screening Methods in Blood Donors- Where Do We Stand Now?
National Journal of Laboratory Medicine, 2019
Introduction: Haemoglobin screening is one of the most important screening tests done for blood donors in order to prevent blood collection from an anaemic donor and ensure an optimum quality of blood product for the recipients. Therefore, it is essential, that an accurate and reliable method for haemoglobin determination among the whole blood donors is selected and established. Aim: To assess the utility and efficacy of the haemoglobin screening methods in blood donors in our institutional setting and to find out the best method taking into account time, cost effectiveness and accuracy of results. Materials and Methods: This is a single centre-based analytical cross-sectional study of pre-donation screening for whole blood donors in the blood bank of a tertiary care teaching hospital at Durgapur, West Bengal, India. A total of 100 consenting potential donors were screened according to the criteria laid down by Drugs and Cosmetic Act of India, 1940. Blood sample which is routinely c...