Near-field fluorescence imaging of genetic material: toward the molecular limit.

نویسندگان

  • N F van Hulst
  • M F Garcia-Parajo
  • M H Moers
  • J A Veerman
  • A G Ruiter
چکیده

Chromosomes, DNA, and single fluorescent molecules are studied using an aperture-type near-field scanning optical microscope with tuning fork shear force feedback. Fluorescence in situ hybridization labels on repetitive and single copy probes on human metaphase chromosomes are imaged with a width of 80 nm, allowing their localisation with nanometer accuracy, in direct correlation with the simultaneously obtained topography. Single fluorophores, both in polymer and covalently attached to amino-silanized glass, are imaged using two-channel fluorescence polarization detection. The molecules are selectively excited according to their dipole orientation. The orientation of the dipole moment of all molecules in one image could be directly determined. Rotational dynamics on a 10-ms to 100-s timescale is observed. Finally, shear force imaging of double-stranded DNA with a vertical sensitivity of 0.2 nm is presented. A DNA height of 1.4 nm is measured, which indicates the nondisturbing character of the shear force mechanism.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Beyond the diffraction limit: far-field fluorescence imaging with ultrahigh resolution.

Fluorescence microscopy is an important and extensively utilised tool for imaging biological systems. However, the image resolution that can be obtained has a limit as defined through the laws of diffraction. Demand for improved resolution has stimulated research into developing methods to image beyond the diffraction limit based on far-field fluorescence microscopy techniques. Rapid progress i...

متن کامل

Investigation of Desulfurization Activity, Reusability, and Viability of Magnetite Coated Bacterial Cells

Background: Magnetic separation using magnetic nanoparticles can be used as a simple method to isolate desulfurizing bacteria from a biphasic oil/water system. Objectives: Magnetite nanoparticles were applied to coat the surface of Rhodococcus erythropolis IGTS8 and Rhodococcus erythropolis FMF desulfurizing bacterial cells, and the viability and...

متن کامل

A Thin Layer Imaging with the Total Internal Reflection Fluorescence Microscopy

Total internal reflection fluorescence microscopy (TIRFM) is an optical technique that allows imaging of a thin layer of the sample with a thickness of about 100-200 nm. It is used in science of cell biology to study cellular processes, especially near the membranes of living cells. This method is based on the total internal reflection phenomenon, where the evanescent wave is generated in the l...

متن کامل

An apertureless near-field microscope for fluorescence imaging

We describe an apertureless near field microscope for imaging fluorescent samples. Optical contrast is generated by exploiting fluorescent quenching near a metallized atomic force microscope tip. This microscope has been used to image fluorescent latex beads with subdiffraction limit resolution. The use of fluorescence allows us to prove that the contrast mechanism is indeed spectroscopic in or...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Journal of structural biology

دوره 119 2  شماره 

صفحات  -

تاریخ انتشار 1997