Why is it important to record the results from the o-tolidine test within 10-15 seconds
To redue the chance of recording a false positive: Natural oxidation from the air can cause the colored form to appear after longer time intervals even in the absence of blood
What is known to cause a premature positive result with tetramethylbenzidine
Bleach
T/F unlike LMG, TMB is a conclusive test
False
The color change for catalytic color test for blood should occur
After the addition of the oxidizer
T/F Increasing the number of steps in a catalytic color test can increase specificity
True
Is the Kasle-Meyer test qualitiative, quantitative or both?
It is only qualitative
When can a catalytic color test yeild a positive result for hemoglobin with saliva?
When there are trace amounts of blood in the saliva
Horseradish will give a false positive for blood after?
The addition of the oxidizer
Most of the forensic literature points to________ as the most specific presumptive test for blood
Leucomalachite green
Animal blood with give a ____ result with O-tolidine
positive
not species specific
Microcrystalline test for blood confirm the presence of:
Heme derivatives
Hemochromagencrystals are________ in appearance.
bright red and feathery
A reason for a negative Teichman test of a known blood stain may be
the sample may have been over heated
Which microcrystalline test does not require hight temperatures for crystallization to occur?
Takayama
Hematin crystal formation in a bloodstain can be induced by using salt____ and ____ under _____conditions
Salt
Heat
Acidic
The specificity of antigens and antibodies is based on their:
Structure
Where on the RBC are antigens located?
on the membrane of the red blood cell
A person's ABO blood type refers to the ____ present
antigen
Type O blood contains what antibodies?
Anti-A and Anti-b
Which presumptive test for blood is considered not to be carcinogenic?
Phenolphthalein
Kastle Meyer test is also known as?
Phenolphthalein test
McPhail's reagent is also known as
Leucomalachite green
A leuco dye in the _____ form is colorless
reduced
A 1:2 serial dilution is started by using 1mL of blood and adding ____ of water
1mL
For blood samples used for species testing the blood should be diluted with buffer until a _____ color is observed
Straw
A sample too strong may overwhelm the antibody
Cross reactivity usually occurs with:
Closely related species
In the Oucherlony diffusion method, more than one band may form if:
different components of the extract have different diffusion coefficients
In a positive chromatographic immunoassay, the Test area "captures" _______ that formed in the sample well and causes a visible reaction.
mobile antigen-antibody complexes
antigen; high dose hook
Acid phosphatatse catalyzes the breakdown of _____ which then reacts with a _____ to produce a colored compound
alpha-naphthyl phosphate ; colorless azo dye
5 minutes
A weak or slow reaction using the AP Spot Test means that the stain:
Could be vaginal fluid
The presence of _____ can inhibit the fluorescing of semen stains while using ALS
bloodstains
What is the best order to process a possible semen stain?
Visual exam
AP testing
PSA testing
What color do nucli stain with H&E?
Purple
SVSA
1:1 million dilution
What color do sperm heads stain with Christmas tree?
Red
What are common things mistaken for sperm heads?
bacteria, e cell nucli and yeast
Amylase is an enzyme that digests:
Starch
How do you differentiate between AMY-1 and AMY-2?
gel electrophoresis
The RSID immunochromatographic test for saliva is sensitive to:
0.001mL of saliva
T/F The starch-iodine test for amylase is semi-quant
True!
Which is more specific SALIgAE or Phadebas tube test?
SALIgAE
Which test for saliva has an unknown mechanism?
SALIgAE
Urine is yellow due to:
urochrome
Normal healthy males urine is a poor source of:
cellular materials
Iodine solution or PAS stain can be used to detect:
the presence of glycogentated e-cells
Glycogentated e-cells stain:
brown
Normal adults produce_____ of urine a day
.75-2 liters
If a slide constains more that _____% glycogenated e-cells it is most likely a vaginal sample
30%
What does DMAC react with?
Urea
Swabs collected from a victim of a vaginal sexual assault approximately 48 hours after the assault will _____ contain semen evidence
possibly
5 to 6 hours
Teichman reagent consists of:
glacial acetic acid and a halide
The teichmann reagent converts_______ to ______
Hemoglobin to hemin (hematin)
The Takayama test uses _____ and ____
pyridine and sugar
The Takayama test induces the formation of ______
Hemochromogen
Hemochromogen is fromed when ______ from hemoglobin reacts with pyridine
ferrous iron
What are the reagents used for the presumptive testing of blood?
Phenolphpthalein
Tetramethylbenzidine
Leucomalachite green
orthotolidine
The Ouchterlony method relies on the radial double diffusion of:
Ab and Ag
Immunoprecipitate are visible where:
Ab-Ag complexes are formed
Azo dyes are:
chemcial compounds with a nitrogen functional group
usually stable
have vivid colors
Reporting a positive result for saliva (general)
Analysis of ___ gave chemical indications for the presence of amylase, a component of saliva
Negative Saliva result
No amylase activity was observed/ Amylase, a constituent of saliva, was not detected on____
-Amylase diffusion quant. positive results for amylase equal/larger to 1:100 dilution
-between 1:100-1:500 dilution
-less than 1:500
Elevated levels of amylase were detected on____, which indicates presence of saliva
Amylase was dectected on ____, Amylase at this level has been observed in saliva as well as other biological fluids
Low levels of amylase were detected on____, Amylase activity at this level is inconclusive for the presence of saliva
Positive AP
Analysis or ___gave presumptive chemical indications for the presence of acid phosphatase, a component of semen
Positive Microscopic ID of semen
Microscopic examination of ____demonstrated the presence of spermatozoa.
Postitive AP and Negative Microscopic and Positive P30
Semen was identified on_____, however micrscopic examination failed to demonstrate the presence of spermatozoa
Positive AP Negative microscope and negative P30
No semen was identified on______
Negative AP
No semen was identified on________
Postitive catalytic color test for blood
Analysis of _____gave presumptive chemical indications for the presence of blood
Postive catalytic color test and positive Takayama/Teichman
Blood was identified on______
Positive catalytic color test for blood and Neg Taka/Tiech
Preliminary tests indicated blood on_____, but further tests could not confirm the identiy of blood
Negative catalytic color test for blood
Analysis of ____failed to give preumptive chemical indications for the presence of blood
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