μL Of Human Blood Research Articles

Magnetized Carbon Nanotube Based Lateral Flow Immunoassay for Visual Detection of Complement Factor B.

The authors describe a magnetized carbon nanotube (MCNT) based lateral flow immunoassay (LFI) for visual detection of complement factor B (CFB) in blood. MCNT was prepared by decorating magnetic Fe3O4 nanoparticles on multi-walled CNT surface and used as a colored tag for LFI. Monoclonal antibody (mAb, Ab1) of CFB was covalently immobilized on the MCNT surface via diimide-activated conjugation between the carboxyl groups on the MCNT surface and amino groups of antibodies. Polyclonal antibody of CFB (Ab2) and the secondary antibody were used to prepare the lateral flow test strips. The assay involved: (1) the capture of CFB in blood with the mAb-functionalized MCNT; (2) magnetic separation of the formed CFB-mAb-MCNT and excess of mAb-MCNT from the blood with an external magnet; (3) lateral flow test to capture the CFB-mAb-MCNT complex on the test zone and the excess of mAb-MCNT on the control zone; (4) Recording the intensities of the produced the characteristic brown bands with a portable strip reader and quantitating the concentration of CFB. The proof-of-concept was demonstrated by testing CFB in the buffer, and the detection limit was 5 ng mL−1 under the optimized analytical parameters. CFB in 1 μL of human blood was detected successfully in 30 min with this LFI and the results had a high correlation with commercial ELISA kit. Thence, the MCNT-based LFI offers a rapid and low-cost tool for detecting CFB in human blood directly.

Optofluidic device for label-free cell classification from whole blood.

A unique optofluidic lab-on-a-chip device that can detect optically encoded forward scattering signals is demonstrated. With a unique design of a spatial mask that patterns the intensity distribution of the illuminating light, the position and velocity of each travelling cell in the flow can be measured with submicrometer resolution, which enables the generation of a cell distribution plot over the cross section of the channel. The distribution of cells is highly sensitive to its size and stiffness, both being important biomarkers for cell classification without cell labelling. The optical-coding technique offers an easy route to classify cells based on their size and stiffness. Because the stiffness and size of neutrophils are distinct from other types of white blood cells, the number of neutrophils can be detected from other white blood cells and red blood cells. Above all, the enumeration of neutrophil concentration can be obtained from only 5 μL of human blood with a simple blood preparation process saving the usual steps of anticoagulation, centrifugation, antibody labelling, or filtering. The optofluidic system is compact, inexpensive, and simple to fabricate and operate. The system uses a commodity laser diode and a Si PIN photoreceiver and digital signal processing to extract vital information about cells and suppress the noise from the encoded optical scattering signals. The optofluidic device holds promise to be a point-of-care and home care device to measure neutrophil concentration, which is the key indicator of the immune functions for cancer patients undergoing chemotherapy.

Optofluidic device for label-free cell classification from whole blood.

We demonstrated a unique optofluidic lab-on-a-chip device that can measure optically encoded forward scattering signals. From the design of the spatial pattern, we can measure the position and velocity of each cell in the flow and generate a 2-D cell distribution plot over the cross section of the channel. Moreover, we have demonstrated that the cell distribution is highly sensitive to its size and stiffness. The latter is an important biomarker for cell classification and our method offers a simple and unequivocal method to classify cells by their size and stiffness. We have proved the concept using live and fixed HeLa cells. Due to the stiffness and size difference of neutrophils compared to other types of white blood cells, we have demonstrated detection of neutrophils from other blood cells. Finally, we have performed the test using 5 μL of human blood. In a greatly simplified blood preparation process, skipping the usual steps of anticoagulation, centrifuge, antibody labelling or staining, filtering, etc., we have demonstrated that our device and detection principle can count neutrophils in whole human blood. Our system is compact, inexpensive and simple to fabricate and operate, having a commodity laser diode and a Si PIN photoreceiver as the main pieces of hardware. Although the results are still preliminary, the studies indicate that this optofluidic device holds promise to be a point-of-care and home care device to measure neutrophil concentration, which is the key indicator of the immune functions for cancer patients undergoing chemotherapy.

Surface modification of polyacrylonitrile fiber for immobilization of antibodies and detection of analyte

Pendent nitrile groups of multifilamentous polyacrylonitrile (PAN) fibers were reduced to amino groups using lithium aluminum hydride for different time of reduction and amine content was estimated by performing acid–base titrations. Attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR) and Differential Scanning Calorimetry (DSC) were used for the characterization of the generated amino groups and thermal properties of the reduced fibers, respectively. The surface morphology of the fibers after reduction and immobilization was characterized using Scanning Electron Microscope (SEM). The newly formed amino groups of the fibers were activated by using glutaraldehyde for the covalent linking of Goat anti-Rabbit IgG-HRP (GAR-HRP) antibody enzyme conjugate. Modified PAN fibers were evaluated as a matrix for sandwich ELISA by using Goat anti-Rabbit antibody (GAR-IgG), Rabbit anti-Goat (RAG-IgG) as analyte and enzyme conjugate GAR-HRP. The fibers reduced for 24 h were able to detect the analyte RAG-IgG at a concentration as low as 3.75 ng mL −1 with 12% skimmed milk as blocking reagent for the optimized concentration of primary antibody GAR-IgG 3 μg mL −1 and peroxidase conjugate GAR-HRP dilution of 8000 fold. The sensitivity, specificity and reproducibility of the developed immunoassay was further established with antibodies present in human blood using Rabbit anti-Human (RAH-IgG) antibody and the corresponding HRP enzyme conjugate. As low as 0.1 μL of human blood was sufficient to perform the assay with the modified fibers.

Development of Automatic Vacuum Driven Blood Extraction System for Blood Sugar Level Measurement

In this study, a health monitoring system (HMS) for diabetes patient is newly developed. Our HMS fabrication extracts the blood through a micro-needle without a pain and measures the blood sugar level accurately. Main subjects of our HMS fabrication are 1) the minimally invasive blood extraction by using the micro-needle with inner diameter less than 100 μm, 2) the handy type automatic blood extraction, and 3) the continuous measurement of the blood sugar level. We adopts a vacuum type blood extraction scheme. The vacuum driven blood extraction unit consists of a) a puncture part to open the vacuum chamber, b) an extraction part, and c) a measurement part. In the results, the vacuum driven blood extraction unit succeeds in extracting 12.7 μl of human blood within 2 seconds. The blood sugar level is measured successfully by using the glucose enzyme sensor. Therefore, a sufficient operating characteristics of our blood extraction device is confirmed.

Development of a New Mobile HMS with Glucose Sensor in Disposable Vacuum Blood Extraction System for Blood Sugar Level Measurement

In this study, a mobile Health Monitoring System (HMS) for the diabetes patient is newly developed. Main subjects of this HMS design are (1) a painless microneedle with inner diameter less than 100 pm, (2) the vacuum blood extraction of 1 μl, and (3) measurement of blood sugar level by using MOS-FET and Glucose sensor. The vacuum blood extraction system with a microneedle and blood sugar sensor is set in a disposable disc cartridge. Simultaneously, the mechanism of vacuum blood extraction was analyzed, the blood flow rate was measured, and the performance of blood sugar sensor was evaluated. Finally, this HMS succeeded in extracting 3 μl of human blood within 0.3 sec and measuring the blood sugar level by the automatic operation.

605 真空吸引型HMSデバイスの開発(J04-1 手術・治療,J04 ライフサポート)

Our health monitoring system (HMS) consists of 1) the painless blood extraction, 2) the handy type automatical blood extraction, and 3) the continuous measurement in blood sugar level by insulin administering. In this study, a vacuum extracting type device for the blood sugar measurement is newly developed, which employ a handy type automatical blood extraction system, such as a mobile HMS for the diabetes patients. The vacuum extracting blood unit, which is built in this vacuum extracting type HMS device, consists of a) the puncture part, b) the extraction part, and c) the base part, and succeeds in extracting 12.7μl of human blood within 2 seconds.

Biological differences in reproductive strategy between the mosquito sibling species Anopheles gambiae sensu stricto and An. quadriannulatus

AbstractFemales of the afrotropical mosquito species Anopheles gambiae Giles sensu stricto and An. quadriannulatus (Theobald) (Diptera: Culicidae) were studied for the effect of blood meal size and the frequency of blood feeding on reproductive development during the first gonotrophic cycle. To standardize the blood meals, meals were administered by enema in some experiments. The effects of insemination, mosquito size, and metabolic reserves at emergence on egg development were also investigated. Maximum insemination was reached after seven days, varying from 62% in An. quadriannulatus to 95% in An. gambiae and was significantly different (P<0.05) between the two species. Insemination had no effect on feeding success. Females of An. quadriannulatus were significantly larger than An. gambiae females (mean wing size 2.90 ±0.01 mm versus 2.82 ±0.01 mm), but the protein, glycogen, and lipid content of newly emerged females of the two species were not significantly different. Without a blood meal, larger females of both species were significantly more likely to develop oocytes up to Christopher's stage II. With one blood meal, 27% of An. gambiae became pre‐gravid and 73% matured eggs. In contrast, all An. quadriannulatus females remained in the pre‐gravid stage following ingestion of one blood meal. Vitellogenesis was significantly reduced in smaller‐sized pre‐gravid An. quadriannulatus compared to larger individuals. When given the opportunity to feed up to three times on three successive days, all females of An. gambiae matured eggs but only 85% of An. quadriannulatus did so. When 1 μl of human blood was administered by enema, none of the females of either species developed eggs. With a single enema of 1.5 μl of human blood, only An. gambiae developed eggs. A similar result was observed with 1 μl and 1.5 μl enemas of bovine blood although some An. gambiae also developed eggs with 1 μl of blood. Anopheles quadriannulatus developed eggs only when given two 1 μl enemas on successive days. However, the percentage of females developing eggs was significantly lower than that of An. gambiae. The implications of these differences in reproductive strategy are discussed in the light of behavioural traits in the field.