scholarly journals A Laboratory Exercise Simulating Antibody and Antigen Reactions of the Ouchterlony Double Immunodiffusion Assay Using Inorganic Salts

2021 ◽  
Author(s):  
Mustafa G. Mujtaba ◽  
Tara Baliban ◽  
Jamini Bhagu ◽  
Michael Herrera
Keyword(s):  
Inorganic Salts ◽  
Protein Antigens ◽  
Double Immunodiffusion ◽  
Precipitation Line ◽  
Laboratory Exercise ◽  
Laboratory Courses ◽  
Classical Technique ◽  
Line Patterns

The Ouchterlony double immunodiffusion assay is a serological technique used in the detection of antibodies and antigens for diagnostic purposes and also used in immunology laboratory courses as a common teaching assay where students observe the geometrical precipitation line patterns that form in the agarose, elucidating degrees of homology between antigens. In this classical technique, students must wait several hours to days to obtain results when protein antigens and antibodies are used.

A new approach for laboratory exercise of pathophysiology in China based on student-centered learning

2015 ◽  
Vol 39 (2) ◽  
pp. 116-119 ◽  
Author(s):  
Jian Chen ◽  
Junhai Zhou ◽  
Li Sun ◽  
Qiuhui Wu ◽  
Huiling Lu ◽  
...  
Keyword(s):  
Active Learning ◽  
Learning Strategies ◽  
Teaching Method ◽  
Student Centered ◽  
Student Centered Learning ◽  
Laboratory Course ◽  
Laboratory Exercise ◽  
Laboratory Courses ◽  
Learning Skill ◽  
Undergraduate Laboratory

Student-centered learning is generally defined as any instructional method that purportedly engages students in active learning and critical thinking. The student-centered method of teaching moves the focus from teaching to learning, from the teachers' conveying course concepts via lecture to the understanding of concepts by students. The student-centered method has been used extensively in lecture courses in China; however, there is little evidence of its use in laboratory courses. The purpose of the present study was to describe the implementation of a student-centered method in a pathophysiology laboratory course. The use of student-centered learning strategies in an undergraduate laboratory course was well received by both students and teachers. Here, students had to take on responsibility for their own learning and, thus, became more accountable. Moreover, they reported increased active learning, skill development, information collection, and retention. In addition, mean scores for the quiz were significantly higher in the student-centered method compared with the traditional teaching method. The shift from teacher-centered delivery to a student-centered model led to a positive change, in which the learners drove the process and were guided, not directed, by the teacher.

scholarly journals Immunological characterization of lysyl hydroxylase, an enzyme of collagen synthesis

1981 ◽  
Vol 195 (3) ◽  
pp. 669-676 ◽  
Author(s):  
Taina M. Turpeenniemi-Hujanen
Keyword(s):  
Chick Embryo ◽  
Cross Reactivity ◽  
Chick Embryos ◽  
Hydroxylase Activity ◽  
Double Immunodiffusion ◽  
Precipitation Line ◽  
Immunological Characterization ◽  
Lysyl Hydroxylase ◽  
Activity Inhibition

Antibodies to pure lysyl hydroxylase from whole chick embryos were prepared in rabbits and used for immunological characterization of this enzyme of collagen biosynthesis. In double immunodiffusion a single precipitation line was seen between the antiserum and crude or pure chick-embryo lysyl hydroxylase. The antiserum effectively inhibited chick-embryo lysyl hydroxylase activity, whether measured with the biologically prepared protocollagen substrate or a synthetic peptide consisting of only 12 amino acids. This suggests that the antigenic determinant was located near the active site of the enzyme molecule. Essentially identical amounts of the antiserum were required for 40% inhibition of the same amount of lysyl hydroxylase activity units from different chick-embryo tissues synthesizing various genetically distinct collagen types. In double immunodiffusion a single precipitation line of complete identity was found between the antiserum and the purified enzyme from whole chick embryos and the crude enzymes from chick-embryo tendon, cartilage and kidneys. These results do not support the hypothesis that lysyl hydroxylase has collagen-type-specific or tissue-specific isoenzymes with markedly different specific activities or immunological properties. The antibodies to chick-embryo lysyl hydroxylase showed a considerable degree of species specificity when examined either by activity-inhibition assay or by double immuno-diffusion. Nevertheless, a distinct, although weak, cross-reactivity was found between the chick-embryo enzyme and those from all mammalian tissues tested. The antiserum showed no cross-reactivity against prolyl 3-hydroxylase, hydroxylysyl galactosyl-transferase or galactosylhydroxylysyl glucosyltransferase in activity-inhibition assays, whereas a distinct cross-reactivity was found against prolyl 4-hydroxylase. Furthermore, antiserum to pure prolyl 4-hydroxylase inhibited lysyl hydroxylase activity. These findings suggest that there are structural similarities between these two enzymes, possibly close to or at their active sites.

scholarly journals Laboratory Exercise to Measure Plasmid Copy Number by qPCR

2021 ◽  
Author(s):  
Benjamin David ◽  
Jinbei Li ◽  
Faisal Masood ◽  
Caroline Blassick ◽  
Paul Jensen ◽  
...  
Keyword(s):  
Copy Number ◽  
Recombinant Dna ◽  
Quantitative Information ◽  
Plasmid Copy Number ◽  
Recombinant Dna Technology ◽  
Plasmid Copy ◽  
Laboratory Activity ◽  
Laboratory Exercise ◽  
Laboratory Courses ◽  
Undergraduate Laboratory

Quantitative PCR (qPCR) has numerous applications in biology. In an education setting, qPCR provides students an opportunity to better understand the PCR mechanism by providing both quantitative information about the reactions and also data to troubleshoot PCRs (e.g., melt curves). Here, we present a relatively short (2-h) laboratory activity to demonstrate qPCR to quantify plasmid copy number (CN) by measuring the cycle threshold ( C T ) values for a genomic gene and a plasmid gene using transformed cells as a template. The activity can be combined with additional laboratory exercises, including bacterial transformation, to create the template to be used in the qPCRs. This lab activity is ideal for undergraduate laboratory courses that include recombinant DNA technology.

The Application of Ultracryotomy to Immunocytochemistry

1973 ◽  
Vol 31 ◽  
pp. 704-709
Author(s):  
R. G. Painter ◽  
K. T. Tokuyasu ◽  
S. J. Singer
Keyword(s):  
Frozen Sections ◽  
Protein Antigens ◽  
Carbon Coated ◽  
Antibody Conjugates ◽  
Ultrathin Frozen Sections

A technique for localizing intracellular antigens with immunoferritin conjugates directly on ultrathin frozen sections of glutaraldehyde-fixed tissues has been developed. This method overcomes some of the limitations of previously described procedures, since it avoids drastic fixation, dehydration and embedding procedures which could denature many protein antigens.Briefly cells or tissues were fixed with glutaraldehyde (0.5 to 2% for 1 hr), and ultrathin frozen sections were cut and mounted on grids covered with carbon-coated Formvar film by the procedure described previously. Such sections were stained with ferritin-antibody conjugates by methods described elsewhere.

The usefulness of high index low symmetry zone axes for holz line analysis

1987 ◽  
Vol 45 ◽  
pp. 384-385
Author(s):  
C. M. Sung ◽  
D. B. Williams
Keyword(s):  
Lattice Parameter ◽  
High Order ◽  
Zone Axis ◽  
High Index ◽  
High Symmetry ◽  
Second Phases ◽  
Line Patterns ◽  
Low Symmetry ◽  
Line Analysis

Researchers have tended to use high symmetry zone axes (e.g. <111> <114>) for High Order Laue Zone (HOLZ) line analysis since Jones et al reported the origin of HOLZ lines and described some of their applications. But it is not always easy to find HOLZ lines from a specific high symmetry zone axis during microscope operation, especially from second phases on a scale of tens of nanometers. Therefore it would be very convenient if we can use HOLZ lines from low symmetry zone axes and simulate these patterns in order to measure lattice parameter changes through HOLZ line shifts. HOLZ patterns of high index low symmetry zone axes are shown in Fig. 1, which were obtained from pure Al at -186°C using a double tilt cooling holder. Their corresponding simulated HOLZ line patterns are shown along with ten other low symmetry orientations in Fig. 2. The simulations were based upon kinematical diffraction conditions.

Imaging nanostructures on ablated kapton polymide

1993 ◽  
Vol 51 ◽  
pp. 872-873
Author(s):  
Daniel L. Callahan ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Polymer Surface ◽  
Grating Period ◽  
Laser Wavelength ◽  
Integrated Devices ◽  
Transmission Electron ◽  
Excimer Laser Irradiation ◽  
Produce Line ◽  
Line Patterns ◽  
Anisotropic Conduction

Excimer laser irradiation has been used to interferometrically ablate submicron line patterns on to Kapton polyimide. Such patterned material may exhibit highly anisotropic conduction as was predicted from previous studies showing enhanced conductivity from uniformly ablated material. We are currently exploiting this phenomenon to create integrated devices using conventional polymers as both dielectrics and conductors. Extensive scanning electron microscopy (SEM) and limited transmission electron microscopy (TEM) have been conducted in order to characterize the morphology of such patterned nanostructures as a function of processing conditions.The ablation technique employed produces an interference pattern on the polymer surface of period equal to half that of a diffraction grating period, independent of the laser wavelength. In these experiments, a 328 nm grating has been used to produce line patterns of 164 nm line-spacings as shown in Figures 1 and 2. A 200 Å Au coating has been used to both prevent charging and, perhaps more importantly, enhance contrast.

Prothrombin Metz : Purification and Characterization of a Variant of Human Prothrombin

1979 ◽  
Author(s):  
M Ribieto ◽  
J Elion ◽  
D Labie ◽  
F Josso
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Factor Xa ◽  
Polyacrylamide Gel ◽  
Cleavage Pattern ◽  
Purification And Characterization ◽  
Double Immunodiffusion ◽  
The Family

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion. Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Val-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin l (Pl) and the appearance of abnormal intermediates migrating faster than Pl.

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