Nonchromatographic radioimmunoassay of unconjugated estriol in plasma, with polyethylene glycol as precipitant.

1976 ◽  
Vol 22 (3) ◽  
pp. 359-363 ◽  
Author(s):  
H S Schiller ◽  
M A Brammall
Keyword(s):  
Polyethylene Glycol ◽  
Clinical Laboratory ◽  
Specific Antiserum ◽  
Low Concentrations ◽  
Coefficients Of Variation ◽  
Free Steroid ◽  
Unconjugated Estriol

Abstract We describe a rapid, reliable radioimmunoassay for unconjugated estriol in plasma. Polyethylene glycol (Carbowax 6000) is used to separate antibody-bound and free steroid. The assay is sensitive (25 pg for standards), precise, and accurate. At high and low concentrations of estriol, intra-assay coefficients of variation were 7.1% and 7.6%, respectively, and inter-assay coefficients of variation were 7.2% and 10.0 %, respectively. Free [3H] estriol is not precipitated by polyethylene glycol. This radioimmunoassay of estriol, with a highly specific antiserum and with polyethylene glycol as the antibody precipitant, is a reliable one-day assay that is practical both for the clinical laboratory and the obstetrician.

Standardization of HER2 Immunohistochemistry in Breast Cancer by Automated Quantitative Analysis

2009 ◽  
Vol 133 (9) ◽  
pp. 1413-1419 ◽  
Author(s):  
Mark D. Gustavson ◽  
Brian Bourke-Martin ◽  
Dylan Reilly ◽  
Melissa Cregger ◽  
Christine Williams ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Clinical Oncology ◽  
Clinical Laboratory ◽  
Breast Cancers ◽  
Her2 Testing ◽  
Coefficients Of Variation ◽  
American Society ◽  
New Guidelines ◽  
Calibration Techniques ◽  
New Generation

Abstract Context.—There is critical need for standardization of HER2 immunohistochemistry testing in the clinical laboratory setting. Recently, the American Society of Clinical Oncology and the College of American Pathologists have submitted guidelines recommending that laboratories achieve 95% concordance between assays and observers for HER2 testing. Objective.—As a potential aid to pathologists for achieving these new guidelines, we have conducted an examination using automated quantitative analysis (AQUA analysis) to provide a standardized HER2 immunohistochemistry expression score across instruments (sites), operators, and staining runs. Design.—We analyzed HER2 expression by immunohistochemistry in a cohort (n = 669) of invasive breast cancers in tissue microarray format across different instruments (n = 3), operators (n = 3), and staining runs (n = 3). Using light source, instrument calibration techniques, and a new generation of image analysis software, we produced normalized AQUA scores for each parameter and examined their reproducibility. Results.—The average percent coefficients of variation across instruments, operators, and staining runs were 1.8%, 2.0%, and 5.1%, respectively. For positive/negative classification between parameters, concordance rates ranged from 94.5% to 99.3% for all cases. Differentially classified cases only occurred around the determined cut point, not over the entire distribution. Conclusions.—These data demonstrate that AQUA analysis can provide a standardized HER2 immunohistochemistry test that can meet current guidelines by the American Society of Clinical Oncology/College of American Pathologists. The use of AQUA analysis could allow for standardized and objective HER2 testing in clinical laboratories.

Enzymic fluorometric continuous-flow assays for blood glucose, lactate, pyruvate, alanine, glycerol, and 3-hydroxybutyrate.

1978 ◽  
Vol 24 (10) ◽  
pp. 1724-1729 ◽  
Author(s):  
B Lloyd ◽  
J Burrin ◽  
P Smythe ◽  
K G Alberti
Keyword(s):  
Blood Glucose ◽  
Perchloric Acid ◽  
Continuous Flow ◽  
Room Temperature ◽  
Automated Analysis ◽  
Low Concentrations ◽  
Coefficients Of Variation ◽  
Analytical Recovery ◽  
One Year ◽  
Fasting Subject

Abstract We describe enzymic fluorometric methods of automated analysis for glucose, lactate, pyruvate, 3-hydroxybutyrate, glycerol, and alanine in perchloric acid extracts of blood. Unmodified Technicon AutoAnalyzer II apparatus is used. The usual concentrations of all these metabolites can be measured in as little as 0.1 ml of blood from a fasting subject. Within-batch and between-batch coefficients of variation ranged from 0.4 to 4.4% for all metabolites except 3-hydroxybutyrate, for which CV's were higher for low concentrations. Analytical recovery of added metabolites ranged from 92 to 98%. Glucose, lactate, alanine, and 3-hydroxybutyrate are stable in perchloric acid extracts for at least 13 days at room temperature, and a year at -20 degrees C; pyruvate shows a 6--8% loss after 3 days and 52% by one year at -20 degrees C; glycerol concentrations were stable at -20 degrees C for at least 13 days. Blank fluorescence is found in perchloric acid extracts of blood, necessitating blank runs for pyruvate, 3-hydroxybutyrate, glycerol, and alanine. The systems are simple to use, relatively inexpensive to operate, and are recommended for any laboratory with high throughput of samples.

Avidin and ovalbumin induction by progesterone in chicken oviduct detected by sensitive immunoenzymometric assays

1991 ◽  
Vol 130 (2) ◽  
pp. 191-197 ◽  
Author(s):  
T. Joensuu ◽  
P. Tuohimaa ◽  
P. Vilja
Keyword(s):  
Body Weight ◽  
Oestrogen Treatment ◽  
Low Concentrations ◽  
Coefficients Of Variation ◽  
Chicken Tissue ◽  
Chicken Oviduct ◽  
Biotin Binding ◽  
The Mean ◽  
Dose Dependent

ABSTRACT This study describes sensitive immunoenzymometric assays (IEMAs) for chicken avidin and ovalbumin, markers of cytodifferentiation and action of progesterone and oestrogen in the oviduct magnum mucosa. The determination range was 0·5–100 ng/ml and the detection limit 0·1 ng/ml in both IEMAs. The intra- and interassay coefficients of variation, measured from chicken tissue supernatants, averaged below 6 and 10% respectively. IEMAs correlated well with the radioimmunoassays for avidin and ovalbumin previously developed in our laboratory, and with the widely used [14C]biotin-binding method for avidin. Using an IEMA, we found avidin induction with low concentrations of progesterone in the differentiated oviduct of oestrogen-pretreated chicks. The induction has not been detected previously by less sensitive methods. Avidin was induced by all given doses of progesterone (0·2–200 mg/kg in vivo for 24 h after a short oestrogen treatment), the response being dose-dependent at doses of 0·2–20 mg progesterone/kg body weight, the maximum avidin production being about 70 μg/g tissue. Ovalbumin was induced at doses of 2–200 mg progesterone/kg body weight without variations in the responses, being about 35 mg/g. The mean content of avidin in the oviduct of laying hens was 58·1 μg/g, and of ovalbumin 74·9 mg/g. Minimal traces of avidin and ovalbumin were found in the oviduct after hatching (0·3 and 5 μg/g respectively); however, progesterone did not have an effect on this expression. Sensitivity, rapidity and practicability, together with non-radioactivity, are the main advantages of the present IEMAs for chicken avidin and ovalbumin. Journal of Endocrinology (1991) 130, 191–197

A paraprotein interference and its management in clinical laboratory / Bir paraprotein interferansı vakasının klinik laboratuvarda yönetimi

2016 ◽  
Vol 41 (2) ◽  
Author(s):  
Özlem Çakır Madenci ◽  
Nihal Yücel ◽  
Lale Köroğlu Dağdelen ◽  
Yusuf Temel ◽  
Aycan Bölük ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Whole Blood ◽  
Total Protein ◽  
Protein Concentration ◽  
Blood Count ◽  
Clinical Laboratory ◽  
Direct Bilirubin ◽  
Total Protein Concentration ◽  
Treatment Patient ◽  
Immunofixation Electrophoresis

AbstractIn the present study we describe a patient who has interference due to paraproteinemia in her labaratory results. In a patient with a total protein concentration of 10.8 g/dL, a direct bilirubin result higher than total was detected. She also had discordant results in her whole blood count parameters. Further investigation was performed on this patient. Presence of any cold agglutinin and cryoglobulin was tested and excluded first. After 2-mercaptoethanol (2-ME) treatment, patient was idendified as Ig-M Kappa monoclonal gammapathy on immunofixation electrophoresis (IFE). Direct bilirubin interference disappeared after removal of the paraprotein by polyethylene glycol (PEG) precipitation. Laboratory specialist should know paraprotein interference and be able to manage it.

scholarly journals Method for the determination of immune complexes by reaction with polyethylene glycol

1982 ◽  
Vol 63 (2) ◽  
pp. 10-13
Author(s):  
B. A. Molotilov ◽  
A. N. Mayansky ◽  
N. D. Pozdnyak ◽  
L. Ch. Samerkhanova
Keyword(s):  
Polyethylene Glycol ◽  
Lupus Erythematosus ◽  
Immune Complexes ◽  
Clinical Laboratory ◽  
Circulating Immune Complexes ◽  
Healthy Donors ◽  
Highly Sensitive ◽  
Photoelectric Colorimeter ◽  
Health And Disease

A study of circulating immune complexes was carried out using a reaction with polyethylene glycol. The method turned out to be simple, highly sensitive and affordable for any clinical laboratory with a photoelectric colorimeter. Analysis of the survey data of 115 healthy donors, 63 patients with rheumatoid arthritis and 16 patients with systemic lupus erythematosus made it possible to establish the level of circulating immune complexes in health and disease. The circulating immune complexes were studied in patients with rheumatism and chronic tonsillitis. To assess the results of the reaction, human aggregated gamma globulin (manufactured by Kazan NIIEM) was used.

Radioimmunoassay of Plasma Testosterone, with Use of Polyethylene Glycol to Separate Antibody-Bound and Free Hormone

1975 ◽  
Vol 21 (6) ◽  
pp. 708-714 ◽  
Author(s):  
Peter H Anderson ◽  
Kimiko Fukushima ◽  
Harvey S Schiller
Keyword(s):  
Polyethylene Glycol ◽  
Steroid Hormones ◽  
Plasma Testosterone ◽  
Partition Chromatography ◽  
Coefficients Of Variation ◽  
Measurable Concentration

Abstract We have developed a reliable radioimmunoassay for testosterone in plasma, polyethylene glycol ("Carbowax 6000") being used to separate antibody-bound and free hormone. Testosterone is separated from interfering steroids, notably dihydrotestosterone, by liquid—liquid partition chromatography on infusorial earth (Celite). The assay is sensitive (9 pg for standards), precise, and accurate. The lowest measurable concentration of testosterone is 350 ng/liter for plasma from men and 70 ng/liter for plasma from women. Intraand inter-assay coefficients of variation were 6.9% and 9.7%, respectively, for plasma from men, and 9.6% and 11.8%, respectively, for plasma from women. Our method for separating antibody-bound and free hormone is practical and convenient and may be generally applicable to all radioimmunoassays of steroid hormones in plasma.

Observational studies on macroprolactin in a routine clinical laboratory

2018 ◽  
Vol 56 (8) ◽  
pp. 1259-1262 ◽  
Author(s):  
Julian H. Barth ◽  
Carys M. Lippiatt ◽  
Stephen G. Gibbons ◽  
Robert A. Desborough
Keyword(s):  
Retrospective Study ◽  
Polyethylene Glycol ◽  
Observational Studies ◽  
Clinical Laboratory ◽  
Median Period ◽  
History Of ◽  
Routine Clinical Laboratory ◽  
Subsequent Sample ◽  
Over Time ◽  
Made In

Abstract Background: It is now recommended that all samples with raised prolactin should be examined for the presence of macroprolactin. We performed a retrospective review of our experience of macroprolactin to determine the incidence and the natural history of macroprolactin. Methods: A retrospective study of macroprolactin was made in a large clinical laboratory. Macroprolactin was measured on those samples where it is requested and where the total prolactin is >1000 mIU/L. Prolactin was measured using the Siemens Centaur and macroprolactin was measured following polyethylene glycol (PEG)-precipitation. Results: The incidence of macroprolactin in samples where the total prolactin was >1000 mIU/L was 36/670 (5.4%). During this period, 12,064 samples were received for prolactin analysis. Over the period since 2006, 22 subjects had a sample with an isolated macroprolactin measurement followed by another sample without macroprolactin after a median period of 0.46 years. Twenty-five subjects had multiple consecutive measurements of macroprolactin lasting a median period of 2.1 years. Fourteen subjects had more than six samples which had been subjected to PEG precipitation. In these subjects, the reproducibility of PEG precipitation over a median of 6 years was 1.1% CV (recovery 75% [26–110] (median [range])). Conclusions: The presence of macroprolactin can change over time and we cannot advise that once a test for macroprolactinemia has been performed that it is not necessary to repeat the investigation if a subsequent sample is hyperprolactinemic; nor can one assume that macroprolactin will not develop even if it has been excluded previously.

scholarly journals Determination of Retinol-Binding Protein in Serum by Kinetic Immunonephelometry with Polyethylene Glycol Pretreatment

1984 ◽  
Vol 21 (6) ◽  
pp. 484-487 ◽  
Author(s):  
M J Hallworth ◽  
Jacqueline Calvin ◽  
C P Price
Keyword(s):  
Polyethylene Glycol ◽  
Detection Limit ◽  
Binding Protein ◽  
Regression Line ◽  
Retinol Binding Protein ◽  
Serum Samples ◽  
Coefficients Of Variation ◽  
Method Yield ◽  
Scattering Material

This work describes the use of polyethylene glycol as a pretreatment reagent to remove endogenous light scattering material from serum samples prior to automated immunonephelometric analysis on a centrifugal analyser. An assay system for retinol-binding protein is described, which allows rapid (10 minutes) quantitation of retinol-binding protein in serum samples with a detection limit of 5 mg/L and between-assay coefficients of variation ranging from 2·9% to 4·0%. The assay range is 5–80 mg/L and accuracy comparisons with a Mancini single radial immunodiffusion method yield a regression line y=0·89x+0·52 ( r=0·98, n=22). The problem of analyte precipitation associated with use of pretreatment regimes is discussed.

scholarly journals Hemoglobin A1c Point-of-Care Assays; A New World with a Lot of Consequences!

2009 ◽  
Vol 3 (3) ◽  
pp. 418-423 ◽  
Author(s):  
Erna Lenters-Westra ◽  
Robbert J. Slingerland
Keyword(s):  
Nurse Practitioners ◽  
Hemoglobin A1c ◽  
Clinical Laboratory ◽  
Point Of Care ◽  
Care Center ◽  
Venous Blood ◽  
Coefficients Of Variation ◽  
Rapid Result ◽  
Performance Results ◽  
Clinical Laboratory Improvement Amendments

Background: Point-of-care instruments for the measurement of hemoglobin A1c (HbA1c) may improve the glycemic control of people with diabetes by providing a rapid result if the performance of the instruments used is acceptable. A 0.5% HbA1c difference between successive results is considered a clinically relevant change. With this in mind, the In2it from Bio-Rad and the DCA Vantage from Siemens were evaluated according to Clinical and Laboratory Standards Institute (CLSI) protocols. Methods: The CLSI protocols EP-5 and EP-9 were applied to investigate precision, accuracy, and bias. The bias was compared with three certified secondary reference measurement procedures. Differences between capillary and venous blood were investigated by an end-user group consisting of nurse practitioners at a diabetes care center. Results: At HbA1c levels of 5.1 and 11.2%, total coefficients of variation (CV) for the In2it were 4.9 and 3.3%, respectively, and for the DCA Vantage were 1.7 to 1.8% and 3.7 to 5.5% depending on the lot number of the cartridges. Method comparisons showed significant lot number-dependent results for the In2it and the DCA Vantage compared with the three reference methods. No overall difference was observed between capillary and venous blood for both methods. Conclusion: Performance results of the In2it and the DCA Vantage showed variable and lot number-dependent results. To maintain the interlaboratory CV of 5% for HbA1c, the Clinical Laboratory Improvement Amendments rules for waived point-of-care instruments should be revised. An obligation for participating in external quality schemes and taking adequate action should be considered for POC instruments that perform poorly.

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