• 대한방사성의약품학회지
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• 제8권2호
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• pp.95-101
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• 2022

Microfluidic radioimmunoassay (RIA) platform called µ-RIA spends less reagent and shorter reaction time for the analysis compared to the conventional tube-based radioimmunoassay. This study reported the design of µ-RIA chips optimized for the gamma counter which could measure the small samples of radioactive materials automatically. Compared with the previous study, the µ-RIA chips developed in this study were designed to be compatible with conventional RIA test tubes. And, the automatic gamma counter could detect radioactivity from the ¹²⁵I labeled anti-PSA attached to the chips. Effects of the multi-layer microchannels and two-phase flow in the µ-RIA chips were investigated in this study. The measured radioactivity from the ¹²⁵I labeled anti-PSA was linearly proportional to the number of stacked chips, representing that the radioactivity in µ-RIA platform could be amplified by designing the chips with multi-layers. In addition, we designed µ-RIA chip to generate liquid-gas plug flow inside the microfluidic channel. The plug flow can promote binding of the biomolecules onto the microfluidic channel surface with recirculation in the liquid phase. The ratio of liquid slug and air slug length was 1 : 1 when the ¹²⁵I labeled anti-PSA and the air were injected at 1 and 35 µL/min, respectively, exhibiting 1.6 times higher biomolecule attachment compared to the microfluidic chip without the air injection. This experimental result indicated that the biomolecular reaction was improved by generating liquid-gas slugs inside the microfluidic channel. In this study, we presented a novel µ-RIA chips that is compatible with the conventional gamma counter with automated sampler. Therefore, high-throughput radioimmunoassay can be carried out by the automatic measurement of radioactivity with reduced radiowaste generation. We expect the µ-RIA platform can successfully replace conventional tube-based radioimmunoassay in the future.

• 약학회지
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• 제29권2호
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• pp.90-95
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• 1985

The development of radioimmunoassay (RIA) for high-density lipoprotein (HDL) in Japanese quail serum will contribute to the screening of drugs acting on cholesterol transport. We have developed a double antibody RIA method for J. quail HDL. The first antibody was raised in rabbit by immunization of HDL isolated by the dextrane sulfate-$Mn^{#}$ precipitation method. For the preparation of raclioiodinated antigen, HDL was further purified by combination of electrophoretic procedure. Using the second antibody raised in goat by rabbit IgG, we have furnished the RIA method for HDL. It showed high specificity and sensitivity of working assay range, 0.1-33.mu.g HDL/tube. There was no correlation between the radioimmunoassay of HDL and the enzyme assay of HDL-cholesterol.

• 한국환경농학회지
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• 제13권3호
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• pp.262-270
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• 1994

Endosulfan의 잔류분석(殘留分析)을 위한 RIA(radioimmuno assay)는 endosulfan alcohol(EA)-BSA conjugate를 항원(抗原)으로 하여 집토끼에서 면역항체(免疫抗體)를 생산(生産)하였다. 생산(生産)된 면역항체(免疫抗體)의 역가(力價)는 1 : 32,000 으로 endosulfan과 EA 이외(以外)의 유사화합물(類似化合物)에서는 거의 반응성(反應性)을 나타내지 않았으며 RIA를 위한 최적(最適) 희석배수(稀釋倍數)는 1 : 2,000 으로 나타났다. RIA의 최적(最適) 배양온도(培養溫度)는 $4\;^{\circ}C$ 이었으며 endosulfan의 검출범위(檢出範圍)는 $1\;ng-20\;{\mu}g$ 이었고 최소검출량(最小檢出量)은 1 ng 이었다. RIA 기법(技法)을 이용(利用)하여 잉어의 각(各) 조직(組織)과 공시수(供試水)에서 실시한 회수율(回收率) 시험(試驗) 결과(結果)는 GLC/ECD나 ELISA를 이용(利用)한 회수율(回收率)보다 우수하게 나타났다. 시료(試料)에서 RIA에 의한 endosulfan의 검출한계(檢出限界)는 0.1 ppb 였다.

• 핵의학기술
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• 제26권1호
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• pp.38-41
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• 2022

Testosterone에 대한 방사면역측정법(radioimmunoassay, RIA) 검사는 남성의 사춘기 지연 및 androgen 결핍 시, 여성과 어린이의 경우 androgen 과잉(다모증) 및 내분비 치료 모니터링 시 시행된다. 현재 본원 핵의학 검체검사실에서는 testosterone RIA 검사를 A사 kit로 사용하고 있지만, 최근 RIA kit의 생산이 중단되거나 공급에 어려움이 발생하여, 다른 회사에서 판매되고 있는 testosterone RIA kit에 대한 유효성 평가 실험을 실시하여 비교하였다. 2021년 10월 서울대학교병원 본원에 의뢰된 검체를 대상으로 실시하였으며, 정밀도, 민감도, 회수율, 직선성, 상관성을 분석하여 비교 평가하였다. 실험 방법은 각 회사에서 제공하는 testosterone RIA kit의 매뉴얼을 준수하였으며, 검체의 양, incubation, 세척(washing) 방법에서 차이가 있었다. 실험 결과 민감도, 직선성, 상관성 실험의 경우 모두 우수한 결과를 나타내었지만, 정밀도와 회수율의 경우 허용범위를 벗어났는데, 이는 낮은 농도의 검체로 실험을 진행하여 벗어난 것으로 사료된다. 이 실험을 바탕으로 각 병원에서 사용 중인 kit가 생산이 중단되거나 공급에 문제가 생길 경우 상호 호환이 가능할 것으로 생각되나, 본 실험에서 고농도의 검체로 실험을 진행하지 못했다는 아쉬움이 있다. 따라서 추후 검사실별로 다양한 농도와 고농도의 검체를 획득하여 추가적으로 실험을 진행해야 할 것으로 사료된다.

• 미생물학회지
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• 제21권2호
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• pp.61-70
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• 1983

Synchronized cat kidney cells chronically infected with feline leukemia virus (FeLV) were used to study virus production, the synthesis of group specific antigen (gag) and envelope (env) proteins, the expression of env protein on the cell surface during the cell cycle, and the stability of viral RNA. As detecting method, we developed the radioimmunoassay (RIA) system using beta-emission of $^{131}I$ and demonstrated the validity of this system by comparison with routine RIA system using gamma-emission of $^{125}I$. The produced virus was analysed by developed RIA interval was determined by measuring reverse transcriptase activity. The results show that infected cells produce the complete virus particle containing products of gag, env and pol genes of FeLV, and maximum virus production occurs during mitosis of synchronized cells. Labeling of the cell surface of synchronized cells with $^{131}I$ shows that the amount of $gp70^{env}$ on the cell surface parallels cellular gorwth. Therefore, the cell cycle-dependent release of virus is not petition RIA of synchronized cells with $^{131}I$ labeled viral proteins synthesis during the cell cycle. The rate of synthesis of gag protein shows three peaks, corresponding to the $G_1,\;late\;S\;and\;late\;G_2$ phases of cell cycle. But the rate of synthesis of env protein dose not change, suggesting that in these cells the synthesis of these two gene products in controlled seperately. In Actionomycin D treated cells, the synthesis of viral proteins decreased sharply from 8 hours after treatment, and the late S and $G_2$ peaks of gag protein synthesis were disappeared. This shows the stability of viral RNA for about 6 hours in the absence of continuing viral RNA synthesis.

• Asian-Australasian Journal of Animal Sciences
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• 제21권9호
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• pp.1286-1295
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• 2008

Leptin is produced by adipocytes and its role in the regulation of lipid metabolism, feed intake, productive and reproductive performance of domestic animal species has been greatly stressed and extensively investigated in recent years. This study was conducted to develop a radioimmunoassay (RIA) for the estimation of plasma bovine leptin and to determine plasma leptin concentration in fattening Japanese Black cattle (Wagyu) and its crossbreds at commercial farms. Relationships of plasma leptin with plasma vitamin A and age of crossbred cattle were also determined. Recombinant bovine leptin (rbleptin) was produced by the E. coli overexpressed leptin as a GST (glutathione S-transferase)-fusion protein. Then antiserum against bovine leptin was obtained by its immunization in rabbits. Using this antiserum, a bovine specific RIA was developed and plasma leptin level was determined in 120 crossbred fattening cattle (WagyuHolstein, 50:50) at commercial farms. The plasma leptin level increased with the age of cattle and its level was greater in the crossbred heifers than in the steers. Plasma vitamin A level was negatively correlated with plasma leptin level in crossbred heifers and steers. This relationship was stronger in heifers than in steers. Plasma leptin was gradually increased with advancing age in fattening Wagyu cattle. In conclusion, development of a bovine specific RIA to estimate plasma leptin will contribute to better understanding of the role of leptin in cattle.

• 대한핵의학회지
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• 제21권2호
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• pp.133-141
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• 1987

To evaluate the values of the thyroid autoantibody measured by radioimmunoassay (RIA) and compare it with hemagglutination method (HA) in the normal and the thyroid disease, data were obtained from total 618 persons; 236 healthy persons, 217 patients with Graves' disease (including 113 patients with undertreated Graves' disease), 100 Hashimoto's disease, 31 thyroid nodule, and 34 simple goiter. RSR kit made in England was used and could be detected to at least 3 U/ml. The positive rates of normal group were antimicrosomal antibody (AMA) 31.8%, antithyroglobulin antibody (ATA) 44.5% by RIA and there was no considerable change in sex and age distribution. In Graves' disease, the positive rates of AMA and ATA were 90.4, 76.9% by RIA, 85, 39% by HA. In Hashimoto's disease, 94,91 % by RIA, and 87,48% by HA, respectively. The autoantibody titer by RIA in thyroid autoimmune disease as well as in normal group was more senisitive than that by HA, especially in ATA. There were linear relationships between the titer of RIA and that of HA in AMA of Graves' disease and AMA and ATA of Hashimoto's disease. There was no relationship among thyroid autoantibody, free $T_4$ index, TBII, and TSH. The titers of AMA and ATA were found to decrease in patients with Graves' disease during the course of antithyroid drug therapy. Of the 236 normal subjects, thirty-seven (15.7%) had concentrations of above 7.5 U/ml in AMA, forty. four (18.6%) above 9 U/ml in ATA. These values were considered as the upper limit for the normal range. In Graves' disease, 82.7, 53.8% were above 7.5, 9 U/ml, respectively; In Hashimoto's disease, 82, 79% were positive. We conclude that RIA was more sensitve than HA in measuring the thyoird autoantibody, but we will study further more for determining the normal range and its interpretation.

• Asian-Australasian Journal of Animal Sciences
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• 제7권1호
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• pp.131-136
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• 1994

In an effort to confirm true oestrus and to detect early pregnancy in Zebu cows (Bos indicus), sequential blood and milk samples were collected at the day of imsemination (Day 0) and days 14, 20 and 24 after insemination. Progesterone was determined in skimmed milk and plasma by solid phase radioimmunoassay (RIA). Of the cows thought to be in oestrus plasma, (n = 46) and milk (n = 58) samples demonstrated low progesterone concentrations ($0.99{\pm}0.11$ and $2.02{\pm}0.14nmol/l$) in 42 (91%) and 52 (90%) cases respectively. Thirty two (76%) and 30 (71%) cows were thought to be pregnant by plasma progesterone RIA ($20.23{\pm}1.03$ and $20.48{\pm}1.01nmol/l$) at days 20 and 24 respectively. At the same period, 40 (77%) and 37 (71%) cows were thought to be pregnant by milk progesterone RIA ($27.82{\pm}1.28$and $28.02{\pm}1.27nmol/l$). Assuming 100% accuracy for rectal examination of pregnancy diagnosis between days 60-65 postservice, the RIA was found to be 84% and 90% accurate for plasma and 84% and 92% accurate for milk at day 20 and 24, respectively. All cows thought to be non pregnant by progesterone measurement were correctly diagnosed. Progesterone assay at 24 days after oestrus may therefore be accurate for early diagnosis of pregnancy in Zebu cows.

• BMB Reports
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• 제30권6호
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• pp.403-409
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• 1997

Studies were undertaken to develop a competitive radioimmunoassay (RIA) and indirect antigen capture enzyme-linked immunosorbent assay (ELISA) for the determination of 5'-deoxy-5'-methylthioadenosine (MTA), which is formed from decarboxylated S-adenosylmethionine by spermidine and spermine synthase. Specific antiserum against MTA was raised in rabbits by immunization with MTA-BSA which was prepared by coupling BSA to oxidized MTA with periodate. Since MTA is oxidized easily to the sulfoxide, the sulfhydryl reagent, DTT. was added to the immunogen. For RIA, immunocomplexes were separated from free MTA by using ammonium sulfate precipitation. The antiserum showed almost no cross-reactivity with a variety of other nucleotides and riboses. But, the level of cross-reactivity of 5'-isobutylthioadenosine (SIBA) was high. These results showed the importance of hydrophobicity adjacent to the 5'-OH for determining antigenicity. The lower limit of detection by this assay was 100 fmol of MTA per tube. Using this assay. MTA levels were more easily and precisely determined in biological samples when compared with HPLC analysis. The RIA procedure is less time consuming. More than 24 analyses can be carried out in 2 h and required only a very small amount of sample ($20{\mu}l$ serum). In ELISA, biotin conjugated MTA-BSA was used as the labelled MTA. The sensitivity limit of this assay was lower than 100 pmol.

• 한국작물학회지
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• 제34권s01호
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• pp.40-47
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• 1989

In spite of the development of highly sophisticated instrument, the precise quantitation of plant hormones still has many difficulties. Due to their high specificity, sensitivity and minimal sample purification steps, immunological assays have been widely applied for plant hormone assay. Enzme-linked immunosorbent assay technique for the determination of plant hormones was developed by Voller in 1978. Immunological assays are accomplished by competition of labeled tracer antigen and unlabeled antigen for a limited number of specific antibodies. The use of enzyme as replacement labels for radioisotopes enabled much of the sensitivity and specificity of radioimmunoassay (RIA) to be retained but without the inherent disadvantage of high capital cost, potential health hazard, and short shelf life of the labeled reactants.