Date of Award
Doctor of Philosophy
Department of Biological Sciences
Dr. Liam McDonnell
Dr. John O'Mullane
Atomic force microscopy [AFM] has become a rapidly developing interdisciplinary field of research in recent years. The technique, including instrumentation and specimen preparation methods, is now more sophisticated and its application has increased dramatically. The key advantage of AFM is in providing three-dimensional images of samples imaged. Both size and shape of samples imaged can be obtained allowing their subsequent quantification. Red blood cells [RBCs] and chromosomes were imaged in this work. A brief overview of the current status of biomedical AFM, has been presented in the review.
Measurement of mean cell volume [MCV] of immobilised red blood cells with the AFM was studied in this project. This parameter increases in value, once a blood sample is taken. Thus, accuracy of the MCV result depends on how soon the hospital laboratory measures the sample. The advantage of measuring MCV with the AFM, is that once an EDTA blood film is made and fixed, soon after taking of the sample, the AFM can measure MCV at any time. Results from automated analysers can be ambiguous, e.g. macrocytosis in a blood film can give a normal MCV, especially when the RBCs are thinner than normal. MCVs were obtained for immobilised RBCs [immobilised mean cell volume, IMCV] with the AFM, and compared with the mobile RBCs measured with the automated hospital analysers. Though the diameter of RBCs decreases to about one-third of its original value, the results of the AFM follow the trends in MCV values.
Many clinical disorders are diagnosed from the morphology of RBCs. The AFM can give surface topography of the RBC thus allowing diagnosis of morphological abnormalities. Chromosomes were also imaged with the AFM, and using line analysis both normal and abnormal human metaphase chromosomes were karyotyped.
O'Reilly-Crowley, Margaret, "Applications of the Atomic Force Microscope within the Fields of Haematology and Cytogenetics" (2000). Theses [online].
Available at: https://sword.cit.ie/allthe/363