Detection of body fluids and toxicology services
One of the most routine service provided by MLSBioDNA is the detection of body fluids such as semen, vaginal secretion, blood and saliva. Following the detection of body fluids , other testing may be required. Tests such as DNA profiling or DNA sequencing, may be required to generate a DNA profile from the body fluids. A DNA profile generated by using 15 STR loci can be considered as unique (no two people will have the same DNA profile except for identical twins. DNA profiles can then be used to compare crime scene samples with victims and suspects.
At BioDNA Laboratory Services scientists have conducted studies that characterise the Maltese population - 24 STRs, Y-Chromosome STRs, X-Chromosome STRs and mitochondrial DNA. Such studies are important for statistical analysis of DNA profiling data.
Recent investment have also included state of the art equipment further improving our methodologies, allowing us to detect alcohol levels in blood and drugs of abuse.
The equipment uses the latest technology allowing for the detection of trace amounts with the highest level of accuracy. More details can be found in the Toxicology section.
Forensic Testing
BioDNA Laboratory Services has been providing forensic services to the Maltese courts for a number of years. It has one of the most advanced analytical facilities in Malta which adheres to strict ISO 17025 standards. It is able to provide a range of independent and innovative DNA and toxicological testing solutions to police forces, legal and criminal justice organisations, private individuals and anyone interested in such a service.
Internationally trained forensic scientists are able to adapt and respond to the individual needs and requirements, providing an accurate, reliable and integral service. Also our ongoing investment into new facilities, technologies and training enables us to deliver the best service to our client with rapid turnaround times.
We have 3 Ph.D’s on staff, both with international recognition and several years of experience in mitochondrial and autosomal DNA analysis, forensic casework and methodologies; and support from local and international crime scene investigators.
Direct Biological samples commonly used in forensic analysis
Hair: Any hair submitted to the lab must have roots or the follicle attached. Hair cuttings will not produce enough DNA and may also inhibit the PCR, due to the large amount of protein found within the cells. Also handle each hair aseptically as possible in order to avoid any contamination of the sample. It is best to utilise a previously alcohol wiped tweezer and placing the hair into a paper envelope. The more hairs available the higher the chance of obtaining a DNA profile, so try to collect as much hairs as possible. A minimum of 10 hairs is normally recommended.
Blood: blood samples can range from whole blood, blood spots on any material, dried blood etc. Fresh blood in a EDTA tube (to prevent clotting) is the best form of sample and will provide a good amount of DNA. The other types, which are normally more common in a crime scene, depend on the condition of the sample especially more so if chemical agents were used prior to the sample collection.
Nails: Feshly trimmed nails work best and have the highest chance of success. These are normaly recommended in the case where the person has recently died or in an assualt case. It is however inperative that the nails are handed with the greatest caution as they can be easily containatied.
Sperm: In the case of dried sperm, the material should be sent directly to the lab in a paper envelope. In the case of liquid semen, the sample can be absorbed by using a clean cotton swab. In both cases avoid storage in humid or plastic bags as molding can occur, resulting in degredation of DNA.
Bone: Bone and teeth samples are one of the most difficult samples to process as a high amount of DNA degradation and PCR inhibitors would be present. The success rate is solely dependent on the condition of the bone. For bone samples, submitting femur or humerus bone is normally recommended however sampling is best to be carried out by a qualified person.
Samples containing DNA used in forensic analysis
Cigarette Butt: Cigarette butts are usually excellent sources of DNA, especially more so if the cigarette was entirely smoked. If the cigarette has ben shared, a mixed profile will result, requiring more specialised analysis. The butt should be sent in a normal paper envelope.
Toothbrush: A toothbrush can be a very good source of DNA, considering that it has been used more then a couple of times. It is important that the brush is air-dried prior to sample submission in order to avoid degredation of the sample. Keep the brush in a paper envelope to allow for air circulation.
Envelope and stamp: Licked envelopes and stamps can provide DNA, provided that no inhibition occurs during PCR. Also it is a common practice nowadays that self-adhesive envelopes are used. These will not provide DNA.
Chewing gum: Chewing gum is a very good source of DNA. Precautions should be taken during sampling as this can easily be contaminated. Use aseptic conditions and store the chewing gum in a paper envelope prior to submission.