MOLECULAR DIAGNOSTICS
Diagnostic techniques are in a time of change. Molecular diagnostic techniques have evolved in step with the discoveries of molecular biology over the past twenty-five years. Molecular techniques are more sensitive and highly specific than classical techniques. In contrast to classical diagnostic techniques open up a whole spectrum of new tools and approaches to the challenging task of diagnosing diseases. As recent outbreaks of major diseases show, rapid and accurate diagnosis is a fundamental requirement in the prevention and management of major disease outbreaks.
Molecular biology offers a wide range of tools applicable to the identification of parasites. The development of these methods was possible due to understanding of the DNA structure and natural replication, transcription and expression mechanisms. These techniques are constantly evolving, allowing for their greater sensitivity and high throughput. It is possible to create assays operating on various taxonomic levels. This versatility is another advantage explaining the vivid interest in these methods. In many cases their superiority over conventional methods is unquestionable since DNA is not subject to stage-related or environmentally induced changes.RAS Lifesciences provides fast, accurate, cutting-edge Molecular diagnostic tests for patient management and research purposes RAS Lifesciences is responsible for molecular analysis of clinical specimens to confirm diagnosis and monitor effects of therapy in various disease entities.
PCR is an invitro method for enzymatically copying defined sequences of DNA. “Insufficient Nucleic Acid” is no longer a limitation for molecular biology research and clinical diagnosis. PCR method at Lab is employed for detection of Bacterial, Viral, Fungal, Parasites, Genetic diseases and Cancer. Real Time PCR is used for qualitative and quantitative analysis of DNA and RNA genomes.
GUIDELINES FOR SPECIMEN COLLECTION
| Sample | Collection device |
Holding Temperature |
Comments |
Swabs |
Use viral transport medium Large swab for throat, lesion, etc. Small wire shaft swab for nasopharynx in young children or urethral samples |
Refrigerate |
Transport medium with swabs can be obtained from RAS Lifecsiences |
Body fluids, BAL, Stool, Urine |
Use sterile leak proof containers |
Refrigerate |
Do not dilute body fluids or BAL in transport medium |
Tissues |
Place in tubes containing liquid transport media to keep tissue moist |
Refrigerate |
Viral transport medium can be obtained from RAS Lifecsiences |
Blood (Leukocytes or plasma) |
Collect in EDTA Vacutainers (lavender top tubes). |
Room temperature |
Sample must be processed as soon as possible after collection. |
Specimen collection instructions for selected specimens
| Nasopharynx swab | Insert swab into nasopharynx, just past point of resistance. Leave in place for 1 min or rotate to dislodge respiratory epithelial cells; remove and place in transport medium. For small children, thin, flexible wire shaft can be used. |
Nasopharynx aspirate |
Use suction pump connected to a catheter through a mucus trap; catheter should be French gauge 8 for infants, French gauge 12 for adults. Insert catheter as far into nose as possible. Specimen should be taken from posterior part of nasal mucosa which is lined with respiratory epithelium, and not from anterior part which is lined with squamous epithelium. Collect as much of NP secretions as possible; do not dilute sample with saline unless necessary. |
Throat swab |
Swab posteror pharyngeal wall, not buccal mucosa, tonsils, tongue or palate. Swab firmly and thoroughly. Throat swabs are suboptimal for DFA testing due to predominance of squamous instead of respiratory epithelial cells obtained. |
Lesion swab |
Clean lesion with sterile saline soaked gauze pad. Unroof vesicles or remove crusts. Firmly swab base and margins of the lesion, obtaining fluid and cells. After sample collection, clean lesion thoroughly with betadine. Do not use disinfectant prior to sample collection or virus may be inactivated. |
Rectal swab |
Stool specimen required for enteric pathogens; rectal swab to swab rectal mucosa can be done for proctitis. |