LabPractical

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 testTrue False

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 specificityTrue False

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

positivenot 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

SaltHeatAcidic

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

StrawA 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

A false negative result in a chromatographic immunoassay due to large amounts of _____ is called the _____ effect.

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

A stain is considered to be negative for AP if no color change associated with the Brentamine reaction occurs after:

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 examAP testingPSA testing

What color do nucli stain with H&E?

Purple

Rapid Stain IDentification immunochromatographic test kits detect _____________.

SVSA

The ABAcard immunochromatographic test kits for p30 are reported to be sensitive up to approximately:

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-quantTrue False

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

The typical maximum time frame in which sperm can be observed in a living victim after an oral assault is _________.

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?

PhenolphpthaleinTetramethylbenzidineLeucomalachite greenorthotolidine

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 groupusually stablehave 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 salivaAmylase was dectected on ____, Amylase at this level has been observed in saliva as well as other biological fluidsLow 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

Speicies testing postive results (human antiserum)

Analysis of ____indicates the presence of human proteins

Speices testing (immunoassay such as hemoglobin or human glycophorin A)

Blood was identified on ___, and: human glycophorin A activity was detected. human hemoglobin activity was detected, Blood from upper primates and domestic ferrets may also cause postive reults with this assay.

Chromotographic ImmunoassayA dye labled______ ______ hemoglobin_____ present in test strip

monoclonal antihuman hemoglobin antibody is present in the test strip

Chromatographic Immunoassay Test area has ______ ______ ______ hemoglobin that captures the Ag-Ab Complex and Ab-Ag-Ab sandwich is formed

The test area has immobilized polyclonal antihuman hemoglobin that captures the Ag-Ab complext and forms a Ab-Ag-Ab sandwich