Specimen Assays

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    Yenny Yustisia

  • Surface characterization

    Contact angle analysis

    Light microscopy

    Electron microscopy

  • Light microscopy

    an instrument that uses visible light and magnifying lenses to examine small objects not visible to the naked eye, or in finer detail than the naked eye allows

  • techniques Transmitted Light Microscopy is the general term used for any

    type of microscopy where the light is transmitted from a source on the opposite side of the specimen to the objective lens

    Inverted observing living cells or organisms

    at the bottom of a large container (e.g., a tissue culture flask) under more natural conditions than on a glass slide

  • Bright Field (Khler illumination) Microscopy

    Dark Field Microscopy

    Phase Contrast

    Polarised Light Microscopy

    Differential Interference Contrast

    Fluorescence Microscopy

  • Confocal Microscopy

  • Electron microscopy

    a microscope that uses accelerated electronsas a source of illumination

    Scanning Electron Microscopy (SEM)

    Transmission Electron Microscopy (TEM)

  • CR




    Electron gun

    Condenser lens

    Objective lens

    Magnification control unit

    Scanning circuit

    Beam deflector


    Condenser lens


    Objective lens


    Intermediate lens

    Projector lens

    Projector screen

    Penyinaran dan pembentukan bayangan pada MO, TEM, dan SEM


  • Contact angle analysis

    The force balance between the liquidvapor surface tension (lv) of a liquid drop and the interfacial tension between a solid and the drop (sl), manifested through the contact angle () of the drop with the surface, can be used to quantitatively characterize the energy of the surface (sv)

  • (a) Wetting system showing forces acting on the liquid drop.

    (b) Nonwetting system with > 90 .

  • The basic relationship describing this force balance is:

    sv = sl + lvcos

    The energy of the surface, which is directly related to its wettability, is a useful parameter that has often correlated strongly with biological interaction.

  • Four possibilities for contact angle measurement: (A) sessile drop, (B) captive air bubble method, (C) capillary rise method, (D) Wilhelmy plate method.

  • Spectrophotometry to measure the amount of light that a sample absorbs.

    The instrument operates by passing a beam of light through a sample and measuring the intensity of light reaching a detector

  • Infrared Spectroscopy

    a simple and reliable technique widely used in both organic and inorganic chemistry

    A Molecul was indentifed by its molecular vibration, based on the absorbtion and intensity of spesific infrared wavelengths

    Provides information on functional groups

  • Assays for protein type and amount

    High-Performance Liquid Chromatography (HPLC)

    Colorimetric assays

    Enzyme-linked Immunosorbent Assay (ELISA)

    Western Blotting

  • High-Performance Liquid Chromatography (HPLC)

    is a technique in analytic chemistry used to separate the components in a mixture, to identify each component, and to quantify each component

    It relies on pumps to pass a pressurized liquid solventcontaining the sample mixture through a column filled with a solid adsorbent material

    Each component in the sample interacts slightly differently with the adsorbent material, causing different flow rates for the different components and leading to the separation of the components as they flow out the column

    Ex: detecting vitamin D levels in blood serum, separating the components of a complex biological sample, or of similar synthetic chemicals from each other

  • Colorimetric assays

    Assays for the presence of a certain protein, based on changes in an observable quantity such as color

    applicable to both organic compounds and inorganic compounds and may be used with or without an enzymatic stage

  • Fluorescent assays

    Similar in concept to colorimetric assays

    Key difference: reaction causes the attachment of a fluorescing molecule (fluorophore) to the protein of interest

  • Enzyme-linked Immunosorbent Assay (ELISA)

    a test that uses antibodies and color change to identify a substance

    For a very specific identification of a protein

  • Western Blotting

    Assay to identify a certain protein after separation of the many proteins contained in a sample through the use of gel electrophoresis

  • Immunostaining

    To identify the location of proteins in tissues and visualized via light microscopy

    A primary antibody is added to the section bind protein of interest

    Second Ab linked to and anzyme or chromophore binds primary Ab

    Imaged under visible light

  • DNA and RNA assays

    To determine gene mutation, damaged gene

    Polymerase Chain Reaction (PCR)

    Southern and Northern Blotting

  • Polymerase Chain Reaction (PCR) &Reverse-Transcription PCR

    To expand the amount of DNA or RNA for that gene to detectable levels

    Polymerase Chain Reaction (PCR) DNAReverse-Transcription PCR RNA