A Method for Preparing Biological Material
This invention relates to a method of preparing biological material obtained from a biological sample, more particularly a blood or sputum sample.
Methods for preparing biological material obtained from blood or sputum samples have been known for decades. These methods are based on multiple steps of preparing and purifying the biological material. For example, normally, the known methods for preparing and purifying nucleic acids include the steps of:
- separating of white cell fraction from the balance of the blood sample through centrifugation;
- lysing the white cell fraction with a detergent;
- digesting the white cell fraction with proteinase;
- extracting the biological material from the digested white cell fraction with organic solvents such as phenol; and
- precipitating the biological material by adding alcohol.
The precipitated biological material is subsequently analysed or stored or transported for later analysis. The disadvantage of these methods;
- owing to the multiple steps, the methods are laborious and time-consuming;
- the addition of enzymes and reagents in the form of detergents and solvents interferes with the analysis of the biological material;
- owing to the relative complexity of the steps, and the nature of the reagents used, the implementation of these methods are confined mostly to laboratories and are not suitable to be exercised in the field where blood samples are collected.
- require regular manual handling of the samples, thereby increasing the risk for laboratory personnel to be infected with hepatitis virus, human immunodeficiency virus (HIV) as well as other pathogens present in the blood samples.
- there is an increased risk for cross-sample contamination, potentially leading to false-positive results. This could have devastating effects in cases where a person is incorrectly diagnosed with HIV.
Objects of the invention
It is accordingly an object of the present invention to provide a method for preparing biological material from a biological sample selected from the group consisting of blood and sputum samples with which the aforesaid disadvantages could be overcome or at least minimised and/or to provide a commercially viable alternative to the known methods.
It is a further object of the invention to provide a simple, relatively fast, efficient and robust method for preparing uncontaminated biological material from the biological sample without the need to apply numerous consecutive steps that necessarily have to be taken in a laboratory environment. A further object of the present invention is to provide improvements to the invention disclosed in the '536 application so that the method could be successfully applied to the biological sample, more particularly the blood sample