mRNA Profiling
Definition
Detection of messenger RNA transcripts specific to particular tissues or body fluids. Endometrial-specific transcripts (LEFTY2, MMP-10 mRNA, others) can distinguish menstrual blood at the RNA level, though mRNA degrades faster than protein in aged stains.
- Detection method
- Reverse-transcription PCR of tissue-specific transcripts
- Key application
- Discriminating between multiple body fluids from a single sample
- Limitation
- Sensitive to RNA degradation in aged stains
Common questions
What does mRNA profiling do in forensics?+
mRNA profiling uses reverse-transcription PCR to detect tissue-specific messenger RNA transcripts in body-fluid stains. By identifying which RNA molecules are present, analysts can determine which body fluids left the stain. A single extract can distinguish multiple fluids at once.
Can mRNA profiling tell menstrual blood from regular blood?+
Yes. Endometrial tissue produces specific RNA transcripts like LEFTY2 and MMP-10 that appear in menstrual blood but not in peripheral blood. Detecting these transcripts confirms the fluid came from the endometrium.
What's the main limitation of mRNA profiling?+
RNA degrades quickly. mRNA breaks down faster than protein, so in aged or degraded stains the transcripts may be too damaged to detect. This makes the test less reliable as samples get older.
Related terms
- ABAcard P30
- A lateral-flow immunochromatographic strip manufactured by Abacus Diagnostics and validated by the Scientific Working Group for DNA Analysis Methods (SWGDAM) for forensic...
- Confirmatory Test
- A test with sufficient specificity to establish the identity of a biological fluid for reporting purposes. Examples include Takayama and Teichmann crystal...
- D-Dimer
- A fibrin degradation product generated when cross-linked fibrin is cleaved by plasmin. Elevated D-dimer in menstrual blood reflects the active fibrinolytic process;...
- Endometrial Shedding
- The physiological process by which the functional layer of the uterine endometrium is broken down and expelled during menstruation. The shedding process...
- Fibrinolysis
- The enzymatic breakdown of fibrin by plasmin, which is generated from plasminogen by tissue plasminogen activator (tPA). Menstrual blood has high tPA...
- Kastle-Meyer (KM) Test
- Phenolphthalein-based colorimetric presumptive blood test relying on haem peroxidase activity. Positive result: pink colour within 2-5 seconds of hydrogen peroxide addition.
- Luminol
- A chemiluminescent reagent (5-amino-2,3-dihydro-1,4-phthalazinedione) that produces blue-white light on contact with haemoglobin-derived iron. Detects blood diluted to 1:10,000,000 or more. Used as...
- Matrix Metalloprotease 10 (MMP-10)
- An endopeptidase of the MMP family involved in extracellular matrix remodelling during endometrial breakdown and shedding. Significantly elevated in menstrual blood and...
- Presumptive Test
- A fast, low-cost, class-specific screen used to triage a caseload before instrumental work begins. Examples are Marquis reagent for opioids and amphetamines,...
- RSID Strips (Independent Forensics)
- Lateral-flow immunochromatographic strips for confirmatory identification of blood (glycophorin A), semen (semenogelin I), saliva (salivary amylase), urine (urea transporter UT-A), vaginal fluid...
- Tissue Plasminogen Activator (tPA)
- A serine protease secreted by endometrial cells and vascular endothelium that converts plasminogen to plasmin. Elevated in menstrual blood relative to peripheral...
Explained in these topics
- Body-Fluid Identification: Presumptive and Confirmatory TestsReverse-transcription PCR detection of tissue-specific mRNA transcripts to identify which body fluids are present in a stain. Allows multi-fluid discrimination...
- Menstrual Blood versus Peripheral BloodDetection of messenger RNA transcripts specific to particular tissues or body fluids. Endometrial-specific transcripts (LEFTY2, MMP-10 mRNA, others) can distin...