Drop Of Blood Research Articles

Proof of Gene Doping in a Mouse Model with a Human Erythropoietin Gene Transferred Using an Adenoviral Vector.

Despite the World Anti-Doping Agency (WADA) ban on gene doping in the context of advancements in gene therapy, the risk of EPO gene-based doping among athletes is still present. To address this and similar risks, gene-doping tests are being developed in doping control laboratories worldwide. In this regard, the present study was performed with two objectives: to develop a robust gene-doping mouse model with the human EPO gene (hEPO) transferred using recombinant adenovirus (rAdV) as a vector and to develop a detection method to identify gene doping by using this model. The rAdV including the hEPO gene was injected intravenously to transfer the gene to the liver. After injection, the mice showed significantly increased whole-blood red blood cell counts and increased expression of hematopoietic marker genes in the spleen, indicating successful development of the gene-doping model. Next, direct and potentially indirect proof of gene doping were evaluated in whole-blood DNA and RNA by using a quantitative PCR assay and RNA sequencing. Proof of doping could be detected in DNA and RNA samples from one drop of whole blood for approximately a month; furthermore, the overall RNA expression profiles showed significant changes, allowing advanced detection of hEPO gene doping.

Bleeding index and the influence on the value of its various factors

The issue of bleeding is so complex that, despite the considerable literature in this area, it is still poorly developed, and yet not only theoretically, but also purely practically, this issue is of great interest: we often see from everyday surgical practice that with the same size and localization of the wound, one organism bleeds profusely, while the other will have only a few drops of blood.

Sessile drops in weightlessness: an ideal playground for challenging Young\u2019s equation

Sessile drop creation in weightlessness is critical for designing scientific instruments for space applications and for manipulating organic or biological liquids, such as whole human blood or DNA drops. It requires perfect control of injection, spreading, and wetting; however, the simple act of creating a drop on a substrate is more complex than it appears. A new macroscopic model is derived to better understand this related behavior. We find that, for a given set of substrate, liquid, and surrounding gas properties, when the ratio of surface free energies to contact line free energy is on the macroscopic scale, the macroscopic contact angle can vary at static equilibrium over a broad volume range. It can increase or decrease against volume depending on the sign of this ratio up to an asymptotic value. Consequently, our model aims to explore configurations that challenge the faithful representativity of the classical Young’s equation and extends the present understanding of wetting.

Comparative analysis between portable glucometers and laboratory method for the measurement of glycemia in cattle

Glucose is considered an important source of energy for cells, fetal growth and milk production in ruminants. Some diseases can be diagnosed by changes in blood glucose levels, which can currently be measured by two methods: the laboratory method and the method using portable glucometers. Therefore, the objective of this study was to carry out a comparative analysis of glucose, measured with a portable glucometer for human use and another for veterinary use, with the laboratory method, considered the gold standard, to assess whether portable equipment can be accurate in blood glucose measurement at field, in cattle. Blood was collected from 17 bovines through the coccygeal vein and the samples were placed in a tube with sodium fluoride for colorimetric enzymatic laboratory analysis, and for the measurement of glucose concentration in portable glucometers, 1 drop of blood was used. The data showed normal distribution by the Shapiro-Wilk test (P = 0.128) and in the comparative analysis provided by the Tukey test (P

A surrogate virus neutralization test to quantify antibody-mediated inhibition of SARS-CoV-2 in finger stick dried blood spot samples

The spike protein of SARS-CoV-2 engages the human angiotensin-converting enzyme 2 (ACE2) receptor to enter host cells, and neutralizing antibodies are effective at blocking this interaction to prevent infection. Widespread application of this important marker of protective immunity is limited by logistical and technical challenges associated with live virus methods and venous blood collection. To address this gap, we validated an immunoassay-based method for quantifying neutralization of the spike-ACE2 interaction in a single drop of capillary whole blood, collected on filter paper as a dried blood spot (DBS) sample. Samples are eluted overnight and incubated in the presence of spike antigen and ACE2 in a 96-well solid phase plate. Competitive immunoassay with electrochemiluminescent label is used to quantify neutralizing activity. The following measures of assay performance were evaluated: dilution series of confirmed positive and negative samples, agreement with results from matched DBS-serum samples, analysis of results from DBS samples with known COVID-19 status, and precision (intra-assay percent coefficient of variation; %CV) and reliability (inter-assay; %CV). Dilution series produced the expected pattern of dose–response. Agreement between results from serum and DBS samples was high, with concordance correlation = 0.991. Analysis of three control samples across the measurement range indicated acceptable levels of precision and reliability. Median % surrogate neutralization was 46.9 for PCR confirmed convalescent COVID-19 samples and 0.1 for negative samples. Large-scale testing is important for quantifying neutralizing antibodies that can provide protection against COVID-19 in order to estimate the level of immunity in the general population. DBS provides a minimally-invasive, low cost alternative to venous blood collection, and this scalable immunoassay-based method for quantifying inhibition of the spike-ACE2 interaction can be used as a surrogate for virus-based assays to expand testing across a wide range of settings and populations.

"Characterization and Classification of Castoff Spatter from Kitchen Knives"

Blood spatter is defined as a distribution of bloodstains that indicate, through a specific arrangement, how the pattern was created [1]. Interpretation of blood spatter and its different patterns plays a crucial role in crime scene reconstruction. For example, the ratio of width to length of a drop can indicate the angle at which the blood drop fell

Evaluation of the LeukoScope for Point-of-Care Measurement of White Blood Cell and Neutrophil Counts in Malawi.

White blood cell (WBC) and neutrophil counts are important laboratory tests used by clinicians to assess a variety of conditions. However, current methods to measure WBC and neutrophil counts are difficult to perform at the point of care, being either cost or labor prohibitive. To meet this need, we developed the LeukoScope: a portable, imaging-based system to measure WBC and neutrophil counts from a drop of blood. Here, we present the performance of the LeukoScope in 136 pediatric and 164 neonatal subjects at a central hospital in Malawi. For pediatric patients, 95.4, 66.7, and 80.0% of samples with normal, low, and high WBC counts, respectively, were correctly identified, and 88.6, 100.0, and 89.3% of samples with normal, low, and high neutrophil counts, respectively, were correctly identified. Accuracy was lower overall for neonatal samples; 92.1, 64.3, and 26.7% of samples with normal, low, and high WBC counts, respectively, were correctly identified, and 73.2 and 78.6% of samples with normal and high neutrophil counts, respectively, were correctly identified. Results of this study show that the LeukoScope can help meet need for point-of-care measurement of WBC counts in pediatric patients and highlight the challenges of point-of-care assessment of WBC counts in neonatal patients.

Effects of Different Methods Used to Take Blood Samples on Blood Glucose Measurements.

The purpose of this study is to compare whether or not there is a difference between venous and capillary blood samples in blood glucose measurements and investigate the effects of different aseptic methods used in skin cleaning before collecting blood samples on measurement results. This quasi-experimental study was conducted with 109 patients. The capillary first and second blood drop values taken from the patients after fasting and at 2 hours following 75 g oral glucose tolerance test (OGTT) and capillary and venous blood glucose values were compared. There was no significant difference between the median venous blood glucose value and the capillary second blood drop value taken after wiping the finger with alcohol. There was no significant difference between the first and second blood drop values of capillary blood glucose 2 hours after OGTT.

Acoustic Levitation: A Novel Approach to Study the Physical Properties of Blood in Normal Subjects and in Patients with Sickle Cell Disease

Acoustic levitation is a novel technique which we have developed for the purpose of measuring physical properties of blood, plasma and red cells in a non-contact setting, which eliminates issues and concerns related to the interaction of blood with non-physiological surfaces. Figure 1 shows a levitated blood drop between the ultrasound transducer and reflector. By exciting drop shape oscillation, we can study its vibrational behavior and infer its viscoelastic properties.Whole blood samples were collected from volunteers in tubes containing Ethylenediaminetetraacetic acid (EDTA) as anticoagulant. Patients' samples were studied using left-over material after a clinically-ordered CBC had been performed. Samples with different hematocrit (Hct) were obtained in the same subject, by removing or adding autologous plasma after centrifugation.To calibrate the device, we compared the results obtained by our instrument with the blood viscosity determination provided by a cone-plate rotational rheometer (HR-2, Hybrid rheometer - TA Instrument). Figure 2 (Left) shows the results from levitator and rotational rheometer.We also compared normal samples with samples of patients with sickle cell disease (SCD) over a wide range of Hct values, obtained by addition or removal of autologous plasma. As shown in Figure 2 (Right), for any given Hct the viscosity measurements obtained by the levitation device were greater in blood of patients with sickle cell disease compared with normal controls.For each sample of blood from patients with sickle cell disease, we assessed viscosity with the levitation device at different values of Hct (autologous plasma addition or removal) and were able to determine the slope of this regression line. We also compared the viscosity value determined at an arbitrary Hct value of 55% among all the clinical samples collected from patients with SCD. As shown in Figure 3, when these data were analyzed as a function of the fetal Hb content of each blood sample (obtained from the total Hb value of the unmodified clinical sample and the % of Hb F determined by HPLC), a clear negative correlation emerged between total Hb F values (in g/dl) and viscosity, measured as either the slope of the regression line or the value at a fixed Hct of 55%. The clinical samples included several patients treated with hydroxycarbamide, showing an important correlation between higher values of Hb F and lower blood viscosity.These studies demonstrate that acoustic levitation is a non-contact technique which can be successfully used to measure physical properties of human blood. We show that viscosity measurements obtained with this new device compare very favorably with traditional rotational viscometer. Furthermore, this new technology can reproducibly measure viscosity over a wide range of Hct values and for any given Hct, it shows that the viscosity of samples from patients with SCD is greater than normal controls. We also show that our measurement is sensitive enough to detect variation in viscosity associated with different absolute values of fetal Hb in blood, and more specifically showing lower viscosity with higher Hb F values, opening the possibility that this technique could be used to determine changes in viscosity associated with hydroxycarbamide therapy in patients with sickle cell disease. [Display omitted] DisclosuresAnsari Hosseinzadeh:National Science Foundation: Research Funding. Brugnara:National Science Foundation: Research Funding. Holt:National Science Foundation: Research Funding.

Pattern formation in drying blood drops

Patterns in dried droplets are commonly observed as rings left after spills of dirty water or coffee have evaporated. Patterns are also seen in dried blood droplets and the patterns have been shown to differ from patients afflicted with different medical conditions. This has been proposed as the basis for a new generation of low-cost blood diagnostics. Before these diagnostics can be widely used, the underlying mechanisms leading to pattern formation in these systems must be understood. We analyse the height profile and appearance of dispersions prepared with red blood cells (RBCs) from healthy donors. The red cell concentrations and diluent were varied and compared with simple polystyrene particle systems to identify the dominant mechanistic variables. Typically, a high concentration of non-volatile components suppresses ring formation. However, RBC suspensions display a greater volume of edge deposition when the red cell concentration is higher. This discrepancy is caused by the consolidation front halting during drying for most blood suspensions. This prevents the standard horizontal drying mechanism and leads to two clearly defined regions in final crack patterns and height profile.This article is part of a discussion meeting issue ‘A cracking approach to inventing new tough materials: fracture stranger than friction’.

The Severity of Malaria and Toxoplasmosis Co-Infections among Pregnant Women in Yaounde, Cameroon

Malaria and toxoplasmosis are two diseases caused by parasites of the same phylum (Apicomplexa). They have severe consequences on the health of pregnant women and their unborn babies. As such, they are of importance for the public health, especially in Sub-Saharan Africa and Cameroon. The aim of this study was to evaluate the severity of toxoplasmosis among malaria-positive pregnant women attending the Biyam-Assi District Hospital. It was a cross-sectional study that took place from May to November 2019 involving 232 pregnant women who voluntarily accepted to take part in the study. Demographic data was collected using structured questionnaires and blood was collectd by finger prick. Thick blood films were prepared for the detection of malaria and the Giemsa-stained slides were read microscopically. A drop of blood was used for the detection of toxoplasmosis using the chromatographic cassette (Rapid Diagnostic Test) and the results were read after 15 minutes. The data obtained was analysed using SPSS version 24. The results showed that the prevalence of toxoplasmosis was 22.84 %. This prevalence didn’t depend on the trimester of pregnancy (P = 0. 08). The prevalence of malaria was 38.9%. No significant difference was observed for either the prevalence or severity of malaria over the three trimesters of pregnancy (p = 0.60 and p = 0.9 respectively). The prevalence of co-infection with malaria and toxoplasmosis was 9.05%. Women without toxoplasmosis were more prone to severe malaria (20.29 %) than their counterparts who had toxoplasmosis (4.78 %) and the difference between these two groups was statistically significant (p = 0.02). The severity of toxoplasmosis was not influenced by the presence of Plasmodium (p = 0. 20). It was concluded that the occurrence and severity of toxoplasmosis in pregnant women does not depend on their malaria serological status. However, the presence of severe malaria in pregnant women depends on their toxoplasmosis status. Indeed, women already infected with T. gondii are less susceptible to malaria than their counterparts who are negative for toxoplasmosis. These findings suggest that T. gondii in a person confers some form of reistance to infections with Plasmodium. It was recommended that the Public Health Ministry in Cameroon could include screening for toxoplasmosis among the routine test for pregnant women in order to improve on the health of mother and baby.

Measurement of Non-Invasive Blood Glucose Level by UWB Transceiver in Diabetic Patient Type-1-

Diabetes is a silent killer and a rapidly increasing global epidemic worldwide. The change in healthy diabetes diet and life-style is only therapy as no permanent treatment. The measuring of the amount of Blood Glucose Level (BGL) continuously is important for diabetes management. In general terms, two types of diabetes can be identified as Type-1- and Type-2-. Type-1- is the most dangerous type and affects (5-10 percent) of the diabetic population; they have to inject or pump insulin themselves. The common method of measuring is glucometer which the sample of blood is taken by clipping patient’s finger and analysis this sample. This invasive method is painful and discomfort for the patient. This article presents a microwave sensor with frequency falls in the range of Ultra-wideband (UWB) spectrum to determine blood glucose level non-invasively (i, e. without giving any sample of blood). Ultra-wideband technology for the Wireless Body Area Network (WBAN) is an important technology due to its advantages in sensing and communication for biomedical applications. The proposed system consists of a piece of microwave resonator that can be placed on the arm of the patient. Then, the first frequency resonance of the sensor is modifying because of many changes are calculated in dielectric blood permittivity and frequency value transferred from the sensor. Relationship between the frequency response and the changing in blood permittivity is observed. This may result in a measurement phase in which the Blood Glucose Level present has a relation with the frequency response value of the sensor. This system showed a clear and accurate outcome. Besides, it is easy to use by patient himself in any time with multiple use without exchanging any part of it, and safe because no taking any drop of blood just put the sensor in touch with patient’s skin without pains, and low cost compared with other methods that measure the glucose level.

Is the Omega-3 Index Higher in Coastal Than Inland US Cities?

ObjectivesHigher omega-3 fatty acid blood levels, as assessed by the Omega-3 Index (O3I, erythrocyte EPA + DHA expressed as a % of total fatty acids), have been linked with lower risk for cardiovascular disease and total mortality. Seafood is an excellent source of EPA and DHA. The purpose of this study was to determine if individuals living in a coastal US city (Newport, RI) with direct access to fresh seafood have higher O3I levels than people living in inland cities. MethodsDried blood spot samples were collected from a convenience sample of people attending a sponsored health fair on the boardwalk in Newport, RI between July and August 2019. Attendees interested in obtaining their O3I signed a consent form before testing and then provided a drop of blood for testing. As a comparator inland group, we used published data (Harris et al. PLEFA 2019;148:30–34) from 7 US cities in the “stroke belt” (note, only one of the 7 cities was coastal, Jacksonville, FL). Dried blood samples were analyzed for the O3I by gas chromatography in both settings. ResultsThe Newport sample included 234 individuals, 50/50 male/female, with a mean (SD) age of 46 (16) years. The 7 cities comparator cohort contained 2177 subjects, with a mean age of 48 (16) years and of those reporting gender, 78% were female. The mean (SD) O3I in Newport was 5.15% (1.37%), whereas in the 7 cities study it was 4.42% (1.12%; P < 0.0001). An O3I of ≤4% (considered low) was found in 21% of the Newport subjects compared to 42% in comparator cohort (P < 0.0001). Relatedly, an O3I of >8% (considered optimal) was found in 3% of the Newport sample compared to 1.2% in the 7 cities study (P = 0.19). ConclusionsThese data support our hypothesis that the O3I is higher in populations living in a coastal city than those living inland. Still, only 3% of individuals with immediate access to fresh seafood had O3I levels in the optimal zone. Given the documented health benefits of having an optimal O3I, increased intakes of EPA and DHA from fish and other dietary sources or supplementation should be recommended. Funding SourcesRB Health (US) LLC.

호손의 「반점」에 나타난 인종, 젠더, 국가

By the 1840s the racial question was at the heart of scholarly discussion in the United States, and few writers could avoid vigorous discussions of superior and inferior races. This paper argues that “The Birthmark,” written by Nathaniel Hawthorne in 1843, is coded the political discourses on race and gender ideology. Aylmer, a newly wedded scientist, is anxious to remove a crimson stain upon Georgiana’s white cheek, which might indicate the ‘one drop of blood’ of African Americans in her artery. Aylmer desperately but unsuccessfully allocates the proper ‘place’ for wife, husband, underworker, white and black, not only from the fear of contamination by crossing the color line but also from the desire to fixate the normative gender roles of the middle-class ideology. His experiment and its failure imply deep anxiety of the white-men-nation to maintain the difference, which is a national fantasy undermined by the ineffaceable birthmark and unforgettable laughter of Aminadab.

Hematuria in Children with Spinal Injury

The presence of red blood cells (RBCs) in urine is hematuria, even in microscopic amounts alarms the patient and parents of the patient, and often prompts physician for many laboratory investigations. Hematuria can be red, dark or cola-colored, or brown known as macroscopic hematuria, and when it is not visible to the unaided eye, it is known as microscopic hematuria. RBCs in urine is one of the most important signs of genitourinary tract disease; however, it is almost never a cause of anemia, since few drops (1 mL) of blood can turn 1 L of urine into red-colored urine. Overall the physician should be alert enough not to overlook serious conditions like neoplasms and underlying bleeding disorder, to avoid unnecessary and often expensive laboratory studies. This article provides an approach to the evaluation and management of hematuria in children, and the detection of preventable and treatable conditions at the earliest to limit the disease progression, and an overall reduction in cost, energy, and anxiety. The patients are spinal cord injured patients with lower urinary tract dysfunction; special consideration of pediatric and elderly populations is presented separately. The target audience is healthcare providers who are engaged in the medical care of patients with spinal cord injury. The mandatory assessment includes medical history, physical examination, frequency-volume chart, urinalysis, blood chemistry, transabdominal ultrasonography, measurement of postvoid residual urine, uroflowmetry, and video-urodynamic study. Optional assessments include questionnaires on the quality of life, renal scintigraphy, and cystourethroscopy. The presence or absence of risk factors for renal damage and symptomatic urinary tract infection affects urinary management, as well as pharmacological treatments. Further treatment is recommended if the maximum conservative treatment fails to improve or prevent renal damage and symptomatic urinary tract infection. In addition, management of urinary incontinence should be considered individually in patients with risk factors for urinary incontinence and decreased quality of life. Keywords: Children; Kidneys, bladder, neurogenic, injuries, spinal cord, spinal cord disorders, ; RBC cast; Red blood cells; Urine, ASIA (American Spinal Injury Association)

Blood Microsampling to Monitor Metabolic Profiles During Physical Exercise.

Monitoring approaches and technical improvements are key factors to improve a sportsman’s health, training, and recovery after an injury. In this study, a targeted metabolomics approach using microsampling with hemaPEN® was developed to measure changes in blood concentrations of nine amino acids and four organic acids before, during, and after exercise. The aim of this research project was to investigate if a reliable monitoring of metabolite levels during sports activity can be achieved by collecting one drop of whole blood at different time points. A hemaPEN device is an easy-to-use and noninvasive microsampling technique designed to collect four accurate and precise blood volumes simultaneously (10.96 µl). Twenty healthy volunteers between 19 and 30 years of age were included in this study. Physical activity consisted in running as fast as possible 1,600 m after 400 m warm-up. One drop of blood was collected at five time points: before exercise, after 800-m running, after 1,600 m, and 30 min and 60 min after finishing the exercise. The influence of physical activity on metabolite levels was evaluated using two ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) methods. Analytical performance criteria such as metabolite stability, method precision, trueness, and accuracy were found to be satisfactory. Expected significant metabolic changes were identified for lactic acid, main TCA cycle intermediates, and some amino acids (e.g., creatinine, choline, and taurine). This preliminary study performed on a small cohort demonstrated a high interest of using microsampling for fluxomics analysis, not only to collect quickly and easily biological samples during sports events but also because it is much easier to store and to process the samples than classical plasma/serum samples obtained by venipuncture. The present results open new avenue for fluxomics analysis in the context of health care.

Reagent-free hemoglobin estimation on a spinning disc

Quantitative estimation of hemoglobin concentration is a commonly required clinical test to assess various manifestations of pathological conditions in blood. While several invasive and non-invasive approaches have been introduced for rapid low-cost determination of hemoglobin levels in patients, these methods have been reported to suffer from various constraints, limiting their applicability for precise quantitative analysis. Methods reporting high levels of quantitative accuracy, on the other hand, are severely challenged for their deployment in resource-limited settings, as these necessitate specialized reagents that demand exclusive storage and transportation facilities as well as trained human resources for deployment in the field. Circumventing these constraints, here we demonstrate a low cost (<$0.01 each test) reagent-free method for hemoglobin estimation on a simple portable unit that can be implemented in under-served locations without sacrificing the fundamental principle of direct evaluation of hemoglobin extracted from the human blood sample. Exploring the fundamental principle of osmotic hemolysis for extraction of hemoglobin from red blood cells, the method harnesses the dynamics of a blood drop on a rotating platform and simple imaging to come up with results in a turn-around time of about 13 min. The efficacy of the device has been justified by validating with established pathological gold standards. These results are likely to pave the pathway of establishing the paradigm of a first-principle based reagent-free evaluation of blood pathology in health and disease.

Anal Fissures in Pediatrics, and Its Non-Surgical Management, A Review Study

The aim of this study is to show the effect of conservative therapy in management of anal fissures in pediatrics.Study samples were patients presenting to Central Teaching Hospital of Paediatrics between Feb. 2012 to Mar.2013. In prospective descriptive-analytical study,50 cases with anal fissures were evaluated in the pediatricsurgery outpatient clinic. All cases were subjected to medical history and clinical examination. The collecteddata were classified in tables. In history we focused on dietary habits , bowel habits , rectal bleeding, painfuldefecation &amp; constipation. The collected data consisted of age, sex, presentation &amp; location of fissure. In clinicalexamination we assessed the site , presence of skin tags &amp; PR if needed. All cases underwent conservativetreatment for anal fissure by using proctocidar ointment locally 2-3 times daily for 3-6 weeks &amp; lidocaine gel2% applied 10 minutes before defecation to minimize the pain. Lactulose syrup was given 2-3 times dailywith meal to soften the stool &amp; Purgative (Dulcolax) orally in addition to dietary habit instructions. Twopatients only not responded to this regimen , so underwent anal dilatation under general anaesthesia. In ourstudy a total of 50 cases (30 cases 60% Males &amp; 20 cases 40% Females) at age between (6 months - 3years)presented in central teaching hospital of pediatrics mainly as pain during defecation. All were evaluated ,diagnosed &amp; managed during the period from Feb.2012 to Mar. 2013 &amp; followed up for 3-6 weeks. In about48 cases (96%) associated with constipation &amp; 2 cases (4%) associated with diarrhea. 34 cases (68%) hadpain during defecation &amp; 27 cases (54%) had bleeding per rectum (streaks of blood or small drops of blood).All Patients were diagnosed clinically by history from parents &amp; local examination. 45 cases of fissures inano were located posteriorly, 3 were anteriorly located &amp; only 2 cases have fissures on both sides. 48 caseshad history of developing symptoms within 2 weeks period &amp; underwent medical management in the formof laxatives e.g. lactulose &amp; purgatives e.g. dulcolax in addition to lidocaine gel 2% which is topicallyapplied for about 3 to 6 weeks resulting in complete healing. 2 cases (4%) only were not responded to thisregimen &amp; needed anal dilatation. We found that an acute anal fissure is more common than chronic inpediatrics. The most common presenting symptoms were pain during defecation &amp; constipation.&#x0D; Conclusion: Anal fissures can be simply and effectively treated medically by topical proctocidar ointmentand lidocaine gel 2% in addition to lactulose syrup &amp; purgative. These are an excellent combination,associated with a low recurrence rate and minimal side effects.

Images de l’Invisible: De l’Antiquité tardive a la fin du Moyen Âge

Images de l’Invisible: De l’Antiquité tardive a la fin du Moyen Âge

COVID-19 serological survey using micro blood sampling

During August 2020, we carried out a serological survey among students and employees at the Okinawa Institute of Science and Technology Graduate University (OIST), Japan, testing for the presence of antibodies against SARS-CoV-2, the causative agent of COVID-19. We used a FDA-authorized 2-step ELISA protocol in combination with at-home self-collection of blood samples using a custom low-cost finger prick-based capillary blood collection kit. Although our survey did not find any COVID-19 seropositive individuals among the OIST cohort, it reliably detected all positive control samples obtained from a local hospital and excluded all negatives controls. We found that high serum antibody titers can persist for more than 9 months post infection. Among our controls, we found strong cross-reactivity of antibodies in samples from a serum pool from two MERS patients in the anti-SARS-CoV-2-S ELISA. Here we show that a centralized ELISA in combination with patient-based capillary blood collection using as little as one drop of blood can reliably assess the seroprevalence among communities. Anonymous sample tracking and an integrated website created a stream-lined procedure. Major parts of the workflow were automated on a liquid handler, demonstrating scalability. We anticipate this concept to serve as a prototype for reliable serological testing among larger populations.