Modern Methods of Plant Analysis / Moderne Methoden Der Pflanzenanalyse: (5 Modern Methods of Plant Analysis / Moderne Methoden der Pflanzenanalyse)

123 phase and hence have no direct bearing on the retention time of solutes. However in gas-solid chromatography, a considerable quantity of the mobile phase may be adsorbed on the surface of the stationary adsorbent which diminishes the column's effective length and ability to retain solutes. In this respect helium has been found to be preferable to most other gases (GREENE and Roy, 1957) because it is adsorbed to the least extent. 3. Packed columns offer a considerable resistance to flow, which may create a pressure differential between inlet and outlet of sufficient magnitude to cause an unfavorable flow rate through a significant length of the column. A reduced inlet/outlet pressure ratio can be obtained by using light molecular weight gases toward which the column packing shows the greatest permeability. The flow rate of the mobile phase is normally adjusted by altering the column inlet pressure, for which purpose commercial pressure regulators of sufficient accuracy are available. Quantitative measurements of the flow rate can be made by a number of methods, including rotameters, orifice meters, soapfilm flow meters and displacement of water. The former two methods are the most con- venient but the least accurate; moreover they create a back pressure and are temperature dependent whereas although the moving soap bubble is cumbersome to employ and unusable for continuous readings, it is preferred when the highest accuracy is required.

Table of Contents:
- Contents.- Emission and Atomic Absorption Spectrochemical Methods..- A. Flame Emission Methods.- I. Lundegardh Method.- II. Flame Photometric Method for Sodium, Potassium and Calcium.- III. Flame Spectrophotometric Method for Magnesium.- IV. Flame Spectrophotometric Method for Iron, Manganese and Copper.- B. Arc Emission Analysis.- I. The Variable Internal Standard, Cathode Layer Method.- II. Direct Cathode Layer Analysis of Plant Ash.- III. The Method of Successive Additions.- C. Spark Emission Methods.- I. Porous Cup Solution Spark Method for Magnesium.- II. The Pelleted Rotating Disc Spark Method.- D. Atomic Absorption Methods.- References.- Mass Spectrometric Methods..- A. Instrumentation.- B. The Sample.- I. Vapor Pressure.- II. Techniques of Introduction.- III. Purity.- C. Origin of Mass Spectra and their Interpretation.- I. Ionization and Fragmentation of Organic Molecules.- II. The Molecular Weight.- III. Simple Fragments.- IV. Rearrangements.- V. Metastable Ions.- VI. Multiple-Charged Peaks.- VII. Mixtures.- VIII. High Resolution Spectra.- D. Specific Applications.- I. Amino Acids.- 1. Qualitative Spectra.- 2. Quantitative Analysis of Amino Acid Mixtures.- II. Amino Acid Sequence in Peptides.- III. Fatty Acids and Related Compounds.- IV. Alkaloids.- V. Miscellaneous Groups.- VI. Determination of Stable Isotopes in the Intact Molecule.- Appendix I.- References.- Plant Spectra: Absorption and Action..- A. Instrumentation.- B. Light Scatter Phenomena.- C. Absorption Spectra.- D. Action Spectra.- E. Fluorescence Excitation Spectra.- References.- Gefriertrocknung..- A. Die biologischen Probleme der Gefriertrocknung.- I. Das intracellular Gefrieren.- II. Die Vitrifikation.- III. Das extracellulare Gefrieren.- IV. Die Trocknung.- V. Die Fehlerquellen.- VI. Testmethoden.- B. Die Vakuum-Sublimation.- I. Theoretische Grundlagen.- II. Apparative Ausrustung.- 1. Der Vakuum-Pumpstand.- 2. Der Trocknungsraum.- 3. Kuhleinrichtungen.- 4. Objektheizung.- 5. Messgerate.- III. Gefriertrocknungsanlagen.- C. Anwendungen.- I. Gefriertrocknung flussiger Praparate.- II. Konservierung von Mikroorganismen.- III. Fixation fur cytochemische Untersuchungen.- IV. Fixation fur elektronenoptische Untersuchungen.- D. Verwandte Methoden.- I. Gefrierkonservierung.- II. Gefriersubstitution.- III. Gefrierschnitte.- Vapour Phase Chromatography..- A. Theoretical Approach.- I. Chromatography in General.- 1. Nature of Stationary Phase: Adsorption vs. Partition.- 2. Mobile Gas Phase : Elution, Displacement and Frontal Analyses.- II. Types of Theories.- 1. Linear vs. Non-Linear Distribution Isotherms.- 2. Ideal vs. Non-Ideal Chromatography.- III. Plate Theory.- 1. Calculation of the Number of Theoretical Plates.- 2. Calculation of the Distribution Coefficient.- 3. Evaluation of a Chromatographic Separation.- IV. Rate Theory.- 1. Eddy Diffusion.- 2. Molecular Diffusion.- 3. Resistance to Mass Transfer.- 4. Temperature, Flow Rate and Pressure.- V. Modifications and Additional Theories.- B. Apparatus Requirements.- I. Detection Systems.- 1. Integral Methods.- a) Titration.- b) Electrical Conductivity.- c) Volume and Pressure Changes.- d) Combustion to Carbon Dioxide.- 2. Differential Detectors - which Consume the Sample.- a) Combustion to Carbon Dioxyde.- b) Hydrogenation to Methane.- c) Flame Emissivity.- d) Hydrogen Flame and Thermocouple.- e) Flame Ionization.- 3. Differential Detectors - which Preserve the Sample.- a) Surface Potential.- b) Dielectric Constant.- c) Impedance of Gas Flow.- d) Heat of Vaporization.- e) Interferometer.- f) Spectroscopy.- g) Radioactivity.- h) Thermal Conductivity - the Katharometer or Diapharometer.- i) Gas Density Balance.- j) High Voltage Ionization.- k) Thermionic Emission.- 1) ? -Ray Ionization.- m) Radio Frequency Detector.- 4. Summary of Detector Characteristics.- II. Gas Phase.- III. Sample Introduction.- 1. Gaseous Samples.- 2. Solid and Liquid Samples.- IV. Stationary Phase.- 1. Column Construction.- 2. Column Dimensions.- 3. Capillary Columns.- 4. Solid Support.- 5. "Active" Solid Adsorbents.- a) Charcoal, Alumina Silica Gel.- b) Molecular Sieves.- c) Tailing Reducers.- d) Chromatothermography.- e) Multiple Columns.- 6. Liquid Phase for GLC.- a) Column Preparation.- b) Selection of the Stationary Phase.- c) Improvement of Peak Symmetry.- V. Temperature Control.- 1. Types of Heating Units.- 2. Programmed Temperature Chromatography.- C. Techniques.- I. Sample Preparation.- 1. Removal of Water.- 2. Esterification.- II. Fraction Collection.- III. Sample Identification.- 1. Use of Standards.- 2. Homologous Series Plots.- 3. Detectors with Different Responses.- 4. Auxiliary Instruments.- 5. Electron Affinity Spetroscopy.- 6. Functional Group Classification.- IV. Quantitative Analysis.- 1. Peak Heights.- 2. Peak Areas.- 3. Overlapping Peaks.- 4. Sloping Base Line and Secondary Peaks.- 5. Instrument Correction Factors.- 6. Internal Standard and Internal Normalization.- D. Applications.- I. Analytic Applications.- 1. Carbon Dioxide and Oxygen : Respiration and Photosynthesis.- 2. Hydrogen, Hydrogen Sulfide, Methane and other Fermentation Gases.- 3. Olefins and Saturated Hydrocarbons.- 4. Nitrogen, Nitrous Oxide, Nitrogen Dioxide and Nitric Oxide.- 5. Ammonia, Organic Amines and Amino Acids.- 6. Alkaloids, Indoles, Purines and Related Compounds.- 7. Carbohydrates.- 8. Lipids, Fatty Acids.- 9. Mono and Dicarboxylic Acids of Low Molecular Weight, and their Derivatives.- 10. Alcohols, Aldehydes, Ketones and Miscellaneous Esters.- 11. Phenyl Propanoid Compounds, Aromatic Acids, Phenols and Related Substances.- 12. Terpenes.- 13. Sulfur Compounds.- 14. Steroids.- 15. Miscellaneous Compounds.- II. Preparative Gas Chromatography.- E. Conclusion.- References.- Ion-Exchange Chromatography..- A. Ion-Exchange Materials.- I. Fundamental Properties of Ion-Exchange Resins.- 1. Chemical Structure.- 2. Physical Properties.- a) Cross-Linking.- b) Exchange Capacity.- c) Particle Size.- II. Ion-Exchange Celluloses.- B. Theory of Chromatographic Procedures.- I. Elution Analysis.- 1. Theory of Elution Analysis.- 2. Conditions for Successful Elution Analysis on Ion-Exchange Resins.- II. Displacement Development.- 1. Completely Ionized Components.- 2. Incompletely Ionized Components.- Comparison of Elution and Displacement Methods.- III. Frontal Analysis.- C. Apparatus.- D. Experimental Procedures.- I. Purification of Ion-Exchange Resins.- II. Preparation of the Column.- III. Operation of the Column.- 1. Elution Analysis.- a) Column Loading.- b) Choice of Solvents.- c) Selection of Temperature.- d) Analysis of Effluent.- e) Regeneration of Ion-Exchangers.- 2. Displacement Development.- a) Selection of Column Size.- b) Concentration of Developer.- c) Size of Fraction.- d) Regeneration of Resins.- E. Some Applications of Ion-Exchange Chromatography.- I. De-Ionization and Preliminary Group Separation of Extracts from Plant Tissues.- Separation into Four Groups.- a) Aromatic Substances.- b) Cationic or Basic Groups.- c) Acidic Substances.- d) Neutral Substances.- II. Separation of a Group of Closely Related Solutes by the Elution Method.- III. Separation of Compounds of High Molecular Weight.- F. Ion-Exclusion.- G. Mechanism of Adsorption of Solutes on Ion-Exchange Resins.- H. Applicability of Ion-Exchange Chromatography.- I. Choice of Ion-Exchanger.- II. Conditions for Chromatography.- III. Rechromatography.- References.- Table 1. Chromatographie grade resins and celluloses.- Molecular Sieving other than Dialysis..- A. Ion-Exchange Materials as Ionic Sieves.- Separations by Ionic Sieving.- B. Molecular Sieving on Starch.- C. Dextran Gels as Molecular Sieves.- 1. Theory of gel Filtration.- 2. Preparation and Operating of Columns.- 3. Some Applications of Dextran Gels as Molecular Sieves.- References.- Dunnschicht-Chromatographie..- A. Methode und Gerate.- I. Die Herstellung dunner Sorptionsschichten.- II. Sorptionsmittel und Bereitung der Streichmasse.- 1. Kieselgel G fur Dunnschicht-Chromatographie "Merck".- 2. Aluminiumoxid G fur Dunnschicht-Chromatographie "Merck".- 3. Kieselgur G fur Dunnschicht-Chromatographie "Merck".- III. Auftragen der Substanzen und Auswahl des Elutionsmittels.- IV. Trennkammer und deren Sattigungszustand.- V. Sichtbarmachung der getrennten Substanzen.- 1. Chemische Verfahren.- 2. Physikalische Verfahren.- a) Aktivitatsmessung.- b) Fluorescenzverfahren.- 3. Biologische Verfahren.- VI. Untere Erfassungsgrenze im Vergleich zur Papierchromatographie.- VII. Dokumentation und allgemeine Auswertung.- VIII. Quantitative Auswertung.- 1. Direkte Verfahren.- 2. Indirekte Verfahren.- B. Spezielle Arbeitstechniken.- I. Zirkular- und Formgebungstechnik.- II. Stufentechnik.- III. Zweidimensionale Arbeitsweise ohne und mit Zwischenreaktion.- C. Anwendungsbereich und Einsatzmoglichkeiten.- D. Anwendungsbeispiele.- 1. Alkaloide.- 2. Aminosauren.- 3. Indol-Auxine.- 4. Steroide und Steroidglykoside.- 5. Lipide.- Literatur.- Paper Chromatography on a Preparative Scale..- A. General.- I. Impurities.- II. Choice of Solvent System.- III. Quantities.- IV. Application of the Sample.- V. Localisation of Bands.- VI. Elution of the Resolved Spots.- B. Multisheet- and Cardboard-Chromatography.- C. Separation on Paper-Packs.- I. Circular Chromatopack Procedure.- II. One Dimensional Chromatopack Procedure.- III. Chromatopile Procedure.- D. Column Chromatography.- I. Columns of Cellulose Powder.- 1. Filling of the Column.- 2. Elution.- 3. Fraction CoUector.- II. Paper Roll Column Chromatography.- E. Continous Paper Chromatography.- F. Accelerated Chromatography.- I. High Temperature Paper Chromatography.- II. Centrifugal Chromatography.- References.- Determination of Size, Shape and Homogeneity of Macromolecules in Solution..- A. Average Molecular Weights.- B. Osmotic Pressure.- I. General Theoretical Considerations.- 1. Definition of Osmotic Pressure.- 2. van';t Hoff';s Law and Derivation of Osmotic Pressure Equation.- a) Ideal Charged Macromolecule-Donnan Equilibrium.- b) Non-Ideal Charged or Uncharged Macromolecule, i.e. the General Case.- 3. Extrapolation to Zero Concentration.- II. Experimental Method.- 1. Types of Osmometers.- a) Dynamic and Static Methods.- b) Membranes.- 2. Difficulties and Precautions.- C. Light Scattering.- I. Fundamental Concepts of the Theory of Light Scattering.- II. Scattering by Dilute Solutions.- III. Fluctuation Theory of Scattering.- IV. Systems of Isotropic Particles Comparable in Size to the Wave Length: Internal Interference.- 1. Dissymmetry Method.- 2. Zimm Method.- V. Polydispersity.- VI. Anisotropy and Depolarisation.- VII. Equations for Polarised Incident Light.- VIII. Scattering from Large Spherical Particles - Validity of Approximate Solution for Internal Interference.- IX. Multicomponent Systems.- X. Charged Macromolecules : Non-Random Systems.- XI. Interacting Systems.- XII. Experimental Methods.- 1. Measurement of Reduced Intensity of Scattering.- 2. Cells.- 3. Volume and Refraction Effects.- 4. Back Reflection Correction.- 5. Calibration of Light Scattering Photometers.- 6. Measurements on Coloured Solutions.- 7. Fluorescent Solutions.- 8. Measurement of Refractive Index Increment.- 9. Clarification of Solutions.- 10. Concentration of Solute.- 11. Measurement of 90 Scattering.- 12. Dissymmetry Method.- 13. Angular Intensity Measurements.- D. Diffusion.- I. Information Available from Diffusion.- II. Diffusion and the Laws of Diffusion.- 1. Types of Diffusion Measurements Carried out in Practice.- a) Steady-State Diffusion.- b) Free Diffusion.- c) Restricted Diffusion.- d) Diffusion during a Sedimentation Velocity Experiment.- 2. Feck';s first Law and Definition of Diffusion Coefficient.- 3. Thermodynamic Interpretation of Diffusion Coefficient.- 4. Fick';s second Law.- 5. Equations for Evaluating Diffusion Coefficients Using Measurements of Free Diffusion Experiments.- 6. Correction of Diffusion Coefficients to Standard Conditions.- a) Correction of D for Viscosity.- b) Correction of D for Temperature.- c) Extrapolation of D to Zero Solute Concentration.- 7. Detection of Heterogeneity by Free-Diffusion Experiments.- III. Experimental Method for Steady-State and Free-Diffusion Experiments.- 1. Steady-State Diffusion - the Diaphragm Cell.- 2. Free Diffusion.- 3. Optical Methods for Free Diffusion.- a) Schlieren Method.- b) Gouy Interference Fringe Method.- c) Rayleigh Interference Fringe Method.- d) Polarized-Light Method.- 4. Zero Time Correction.- 5. Method of Expressing Results.- 6. Example of Calculation of Reduced Height-Area Ratio.- From Schlieren Photographs of an Artificial Boundary in the Ultracentrifuge.- IV. The Use of the Diffusion Coefficient in Determining Molecular Weight.- 1. Combination of Sedimentation and Diffusion Coefficients to give Molecular Weight.- 2. Approximate Method Using Stokes'; Law.- 3. Combination of Diffusion Coefficient and Intrinsic Viscosity.- 4. Diffusion Coefficient Relationship to Molecular Shape.- V. Factors Contributing to Uncertainty in the Experimental Determination of the Diffusion Coefficients of Macro-Molecules.- 1. Interaction of Solute Flows.- 2. Charge Effects with Macromolecules.- 3. Initial Conditions - Dialysis.- 4. Purity of Solute.- E. Ultracentrifugation.- I. Information Available from Sedimentation, and General Aspects of Sedimentation Analysis.- II. The Two Facets of Sedimentation Analysis.- III. Non-Ideal Behaviour and Charge Effects.- IV. Sedimentation Velocity.- 1. The Boundary and Optical Means of Observation.- 2. The Sedimentation Coefficient and its Experimental Evaluation.- 3. Minimum Requirements from Sedimentation Analysis which must be Fulfilled if a Substance is to be Claimed as Homogeneous with Respect to Sedimentation Coefficient.- 4. More Stringent Tests which must be Satisfied by a Homogeneous Material.- 5. Expressions of the Degree of Heterogeneity of a Material.- a) Actual Distribution of Sedimentation Coefficients.- b) Method of Indicating Departure of Sedimentation Curve from that Representative of Homogeneity.- 6. Density Differences as a Test of Heterogeneity. Equilibrium Sedimentation in a Density Gradient.- V. Equation for Determining Molecular Weight from Sedimentation Velocity.- 1. The Svedberg Equation.- 2. Approximate Methods.- 3. Partial Specific Volume.- VI. Sedimentation Equilibrium and Approach-to-Equilibrium.- 1. Klainer-Kegeles Calculation of the Archibald Method when a Plateau Region is Still Present.- 2. A General Method of Calculation which can be Applied throughout the Cell whether or not a Plateau Region Exists.- 3. Method of Calculation of Molecular Weight which Gives the Weight-Average Molecular Weight of the Whole Solute once Equilibrium has been Attained.- 4. Method of Calculation which Gives the z-Average Molecular Weight of the Whole Solute once Equilibrium has been Attained.- VII. The Proportions of Components in a Sedimenting Mixture.- 1. The Johnston-Ogston Effect.- 2. Velocity Sedimentation in Systems of Reversibly-Interacting Components.- F. Viscosity.- I. Newtonian and Non-Newtonian Viscosity.- II. Functions of Viscosity.- III. Viscosity Relations for Particles of Different Shapes.- IV. Experimental Methods.- G. Particle Shape from Hydrodynamic Measurements.- I. Spheroidal Molecules.- 1. Frictional Coefficient.- 2. Intrinsic Viscosity.- 3. Combination of Hydrodynamic Methods to Give Particle Shape.- II. Randomly-Coiled Molecules.- Sectional References.- Optical Rotatory Dispersion. Its Application to Protein Conformation..- A. Mean Residue Rotation of Polypeptides and Proteins.- B. Optical Rotatory Dispersion - Drude Equation.- C. Rotatory Properties of Synthetic Polypeptides.- D. Optical Rotatory Properties of Proteins.- Existence of Structures in Proteins other than the Right-Handed ?-Helix and Random Coil.- E. Temperature Dependence of Optical Rotation.- F. Measurement of Optical Rotation.- G. Treatment of Data.- References.- Diffuse Rontgenkleinwinkelstreuung..- A. Theorie.- I. Die reine Partikelstreuung.- II. Dichtgepackte isotrope Systeme.- III. Orientierte Objekte.- B. Experimentelle Methodik.- I. Die wichtigsten Kameratypen.- 1. Kameras vom Lochblendentyp.- 2. Kameras vom Spaltblendentyp.- II. Die Monochromatisierung der Strahlung.- 1. Monochromatisierung durch Kristallreflexion.- 2. Verwendung des Rossschen Filterdifferenzverfahrens.- 3. Aussonderung der gewunschten Strahlung durch einen Impulshohendiskriminator in Verbindung mit einem Proportionalzahlrohr.- III. Die Registrierung.- 1. Photographische Messung.- 2. Impulszahlung.- C. Anwendungsbeispiele.- I. Homodisperse Proteinlosungen.- II. Homodisperse Pflanzenviren.- III. Dicke der Proteidlamellen von isolierten Chloroplasten.- IV. Bestimmung der Micelldicke in "luftgequollener" Cellulose.- V. Bestimmung der Micelldicke in "wassergequollener" Cellulose.- VI. Bestimmung der Micelldicke nativer Cellulose aus dem Ranbyschen Micellpulver und aus gequollenen Ramiefasern.- VII. Gehaltsbestimmung der Micellen aus der Anisotropie der Kleinwinkelstreuung bei Cellulosefasern.- VIII. Orientierungsbestimmung aus der Anisotropie der Kleinwinkelstreuung.- Literatur.- Methodes Calorimetriques pour l';Analyse des Vegetaux..- I. Appareillage.- II. Thermogenese de Germinations.- III. Gradients de Thermogenese dans les Organes en Croissance.- IV. Thermogenese des Cultures Bacteriennes et Myceliennes; Fermentations.- V. Chaleurs de Combustion d';Organes et de Produits Vegetaux.- VI. Conclusion.- References Bibliographiques.- Surface Factors Affecting the Penetration of Compounds into Plants..- A. Effect of Molecular Structure on Permeation.- B. Effect of Surface and Interfacial Factors on Potency of Treatments.- I. Factors Affecting Deposition of Materials on Foliage.- II. Factors Affecting the Absorption of Materials by Foliage.- 1. Nature of the Formulation Applied.- 2. Nature of the Plant Surface.- C. Surface and Interfacial Tension.- I. Measurement of Surface Tension.- 1. Capillary Methods.- 2. Falling Drop Method.- 3. The Ring Method.- II. Measurement of Interfacial Tension.- 1. Capillary Method.- 2. Falling Drop Method.- 3. Ring Method.- D. Wetting and Spreading.- I. Wetting and the Contact Angle.- II. Water Repellency.- III. Spreading and the Spreading Coefficient.- IV. Penetration of Porous Surfaces.- References.- Tissue and Single Cell Cultures of Higher Plants as a Basic Experimental Method..- A. History of the Method.- B. Types of Cultures.- C. Tissue Culture Media.- I. Concentrated Stock Solution.- II. Preparation of Basic Media.- III. Supplements to the Basic Media.- IV. Purity of the Water.- V. Types of Culture Vessels.- VI. Cleaning of Glassware.- VII. Aeration of the Cultures.- VIII. Sterilization of Media.- D. Isolations of Organs, Tissues and Cells.- I. Isolation and Transfer Tools.- II. Organ and Tissue Culture.- III. Embryo Cultures.- IV. Root Tip Cultures.- V. Stem Tip Cultures.- VI. Other Miscellaneous Cultures.- VII. Callus Cultures.- VIII. Some General Precautions.- E. Transfer and Maintenance of Cultures.- I. Callus Formation.- II. Testing for Sterility of Cultures.- F. Single CeU Cultures.- G. Growth Measurements.- H. Requirements for Growth of Callus Cultures.- I. The Acidity of the Medium.- II. Temperature.- III. Light.- IV. Inorganic Nutrition.- V. Carbohydrate Nutrition.- VI. Nitrogen Nutrition.- VII. Vitamins and Growth Substances.- VIII. Nucleic Acids, Purines and Pyrimidines.- IX. Complex Extracts.- J. Some Applications of Tissue and Cell Cultures.- I. Respiration and Metabolism.- II. Polarity and Organ function.- III. Studies of Plant Diseases.- IV. Single Cell Cultures of Higher Plant Cells.- K. Resume.- References.- Immunological Methods..- A. The General Principles of Immunological Methods.- B. Purification of Antigens, Immunization of Animals and Treatment of Antisera.- I. Purification of Antigens.- II. Production of Antibodies.- 1. Choice of Animals.- 2. Immunization of Animals.- Adjuvant Method.- III. The Preparation of Antisera.- 1. Bleeding.- 2. Separation of Serum.- 3. Storage of Serum.- IV. Pretreatment of the Antisera.- 1. Isolation and Concentration of Antibodies.- 2. Absorption of Antisera.- 3. Labelled Antisera.- a) Production of Fluorescein Labelled Antiserum.- b) Production of Ferritin Labelled Antibodies.- C. Serological Methods.- I. Precipitin and Agglutinin Reactions.- 1. Considerations of the Mechanism of the Precipitin Reaction.- 2. Reactions in Free Liquids.- a) In Tubes.- b) In Droplets.- c) The Agglutinin Technique.- 3. Reactions in Gels.- a) Simple Diffusion in One Dimension.- b) Double Diffusion in One Dimension.- c) Double Diffusion in Two Dimensions.- d) Interpretation of Precipitation Patterns in Double Diffusion.- e) Immunoelectrophoresis in Gels.- 4. Localization of Antigens in Tissues.- II. The Complement Fixation Test.- III. Serological Methods Based on Electron Microscopy.- IV. Serological Methods Based on Specific Activities of Antigens.- D. Antigen-Antibody Reactions in Sensitized Animals or Their Organs.- E. Quantitative Determinations of Antigens.- I. Dilution-End-Point Test.- II. ?-Optimum Test.- III. The Determination of the Amounts of Specific Precipitate.- F. Measurements of the Amounts of Antibodies in Sera.- I. The Titre of the Serum.- II. From the Determination of the ? Optimum.- G. Methods for the Determination of Relationships between Antigens.- H. Immuno-Chemical Criteria of Purity of Antigens.- J. Applications.- I. Serology in Relation to Taxonomy of Higher Plants, Fungi and Bacteria.- II. Identification of Antigenics Substances from Plants.- 1. Proteins in General.- 2. Toxins and Allergens.- 3. Substances with Enzymatic Properties.- 4. Plant Viruses.- III. Serological Studies of Cell Products.- IV. Serological Applications in the Analysis of Biosynthetic Processes.- 1. Biosynthesis during Multiplication of Plant Viruses.- 2. Localization of Virus Synthesis within Intact Plant Cells.- 3. Antigens Associated with Fungus Infection.- 4. Biosynthesis of Enzymes.- 5. The Study of the Process of Vernalisation.- Concluding Remarks.- References.- Polarography and Tensammetry..- A. Principles of Polarography.- I. (A) D.C. Polarography.- 1. General.- 2. Types of Polarographic Processes.- 3. Applicability of D.C. Polarography.- 4. Specialized Techniques.- II. A.C. Polarography.- III. Tensammetry.- Combined A.C. Polarographic-Tensammetric Processes.- B. The Practice of Polarography.- I. Measuring Outfit.- 1. D.C. Polarography.- a) A Simple, Cheap Polarograph.- b) Useful Additions to the Simple Polarograph.- 2. A.C. Polarography.- II. The Polarographic Cell.- III. Testing of the Outfit.- IV. The Taking of Polarograms.- V. Evaluation of Polarograms.- VI. Polarographic Titrations.- VII. Chromato-Polarography.- VIII. Common Faults and their Remedies.- 1. Total Interruption in the Circuit.- 2. Irreproducibility of Results.- References.- Fallout Contamination in Plants..- A. Factors which Influence the Fallout Contamination of Plants.- I. Properties and Characteristics of Fallout.- II. Plant Factors which Affect Contamination.- B. Methods of Estimating Gross Fallout Contamination in Plant Material.- I. Counting.- II. Autoradiography of Contaminated Specimens.- C. Methods of Estimating the Individual Radionuclides in Contaminated Plant Materials.- I. Radioactive Strontium.- 1. Sample Preparation.- 2. General Method of Bryant, Morgan and Spicer (1959)..- a) Preparative Procedure.- b) Counting Procedure.- c) Addenda.- II. Iodine-131.- 1. ?-Spectrometry.- 2. Radiochemical Method.- III. Caesium-137.- References.- Sachverzeichnis (Deutsch-Englisch).- Subject Index (English-German).- Table des Matieres pour la Contribution: H. Prat, Methodes Calorimetriques pour l';Analyse des Vegetaux.