Principles of Microscopy
- Microscopes are essential tools for visualising blood cells and other microscopic structures.
- Microscopes include optical microscopes (bright-field and dark-field) and electron microscopes. Bright-field microscopes are most common in haematology.
- Optical Microscopes use light to pass through a specimen, magnified by lenses, to provide a detailed image. Compound microscopes use multiple lenses for higher magnification.
- Magnification enlarges an image’s appearance, whilst resolution distinguishes between closely situated objects, expressed in micrometres (μm).
Understanding and Operating an Optical Microscope
- A typical optical microscope is composed of a head (houses eyepieces and prisms), base (provides stability and houses the light source), and arm (connects the head to base and serves as a handle).
- Additional Components include the diaphragm (regulates light), condenser (focuses light on the specimen), stage (holds the slide), nosepiece (holds objective lenses), objective lenses (provide magnification), eyepiece (further magnifies image), focus knobs (adjust focus), and filters (enhance contrast).
- Oil Immersion is used with high-power lenses (50x and 100x) to reduce light refraction and enhance resolution.
Effective Blood Film Reporting
- Blood film reporting combines scientific knowledge and technical skills to provide a comprehensive analysis for diagnosing various conditions. Reliability, consistency, and understandability are key principles.
- Standard operating procedures (SOPs) provide a structured framework for analysing and reporting blood films, ensuring all personnel adhere to the same standards.
- Training and competency assessments are essential for standardising blood film reporting and ensuring proficiency in identifying and describing different cell types.
- Internal and external quality assessments maintain high standards. External assessments involve proficiency testing and audits by organisations like the ISO (e.g., ISO 15189:2022).
- Minimise ambiguity through experience and knowledge of normal cells and interpret findings in the context of other cells and overall abnormalities.
- Ensure clarity and comprehensiveness by using the correct terminology and a structured format, including patient information, clinical details, morphological findings, and conclusions with actionable recommendations.