Investigating CSI – Background material Table of Contents I ...

Recommendations

Info

Saliva Evidence Amylase activity: The most common tests for the identification of saliva are dependent upon the detection of amylase (1-3). Confirmation of amylase means that results are consistent with saliva and then consistent with oral sex. A high level of amylase activity is usually indicative of the presence of saliva. With the exception of feces, no other body fluid approaches the level of amylase activity in dried stains. Amylase is a very stable enzyme and can be detected even on dried articles. Salivary amylase: As with most enzymes, the function of salivary amylase can be deduced from the name. "Salivary" refers to the fact that it is found in saliva. The suffix "ase" is usually added to the end of enzymes as an indication that the name refers to an enzyme. Amylose is a kind of starch in which glucose monomers are joined by α(1—4) linkages. α-Amylase (α-1,4-glucan 4glucanohydrolase, EC 3.2.1.1) is an enzyme that degrades starch to oligosaccharides and in turn to maltose and glucose by hydrolyzing α-1,4-glucan bonds. In digestion, the role of α-amylase is primarily the first reaction of this process, generating oligosaccharides that are then hydrolyzed by other enzymes. Salivary amylase is very specific in the way it breaks down starch to glucose. It inserts a water molecule at the α(1—4) linkage closest to the end of the amylose molecule thus releasing a glucose molecule. We can measure this break down to determine if salivary amylase is present (see figure below). Positive amylase tests confirm amylase activity, which is consistent with saliva. The amylase assay is very sensitive and can detect amylase activity down to a final concentration of 1 x 10 -4 U/mL (0.001 units). Amylase concentration in human saliva is 42–59 U/mL (4). One unit (U) is defined as the amount of enzyme required to liberate 1 mg of maltose from starch in 3 minutes at 20° C, at pH 6.9. The mechanism of α-amylase. The enzyme protonates (hydrolizes) the acetal linkage between the n-sugar residue (sugar on the left) and the rest of the saccharide chain to yield a free glucose residue to convert to energy. References 1. Brauner, P., "The Evidence Notwithstanding--A case Report on a Rape," Journal of Forensic Sciences, JFSCA, Vol. 37, No.1, Jan. 1992, pp.345-348 32
2. Brauner, P.& Gallili, N., "A Condom--the Critical Link in a Rape," Journal of Forensic Sciences, JFSCA, Vol. 38, No.5, September 1993, pp.1233-1236. 3. "Forensic Science Symposium On The Analysis of Sexual Assault Evidence", Proceedings, Forensic Science Research and Training Center, Laboratory Division, FBI Academy, Quantico, Virginia, 1983, July 6-8 4. McCloskey, K.L. & Muscillo, G.C. & Noordewier, B., "Prostatic Acid Phosphatase Activity in the Postcoital Vagina," Journal of Forensic Sciences, 1975, vol.20, p.630-636 Source: http://www.dnatesting.biz/Semen_Sperm_ID/semen_sperm_id.html 33
Page 1 and 2: Investigating CSI - Background mate
Page 3 and 4: convict the killer of Gill Dando wa
Page 5 and 6: A forensic scientists needs a honou
Page 7 and 8: lond, is also wearing Air Jordans w
Page 9 and 10: of unidentified remains with the pr
Page 11 and 12: Matching DNA Proving that a suspect
Page 13 and 14: Creating a DNA Profile: The Basics
Page 15 and 16: with thymine and guanine with cytos
Page 17 and 18: power is the combined analysis of a
Page 19 and 20: of DNA profile comparisons done by
Page 21 and 22: II. Tools and Techniques for DNA Fo
Page 23 and 24: p30 Test Unlike the presumptive aci
Page 25 and 26: Specificity refers to how many othe
Page 27 and 28: expected to occur when using your c
Page 29 and 30: helps to bind oxygen as well.) When
Page 31: chemical reaction, but in order to
Page 35 and 36: DNA Extraction Techniques Organic-b
Page 37 and 38: C. Quantification of DNA Southern B
Page 39 and 40: Southern Up Close In this simplifie
Page 41 and 42: 2. cDNA is denatured at more than 9
Page 43 and 44: SYBR-green SYBR green is another me
Page 45 and 46: Let's look at two people and the se
Page 47 and 48: at this locus and a different sized
Page 49 and 50: These loci are located on the same
Page 51 and 52: Short Tandem Repeat (STR) Analysis
Page 53 and 54: The other two PowerPlex16 groups of
Page 55 and 56: The Federal Bureau of Investigation
Page 57 and 58: eference sample from the standard s
Page 59 and 60: III. Interesting Cases Using DNA Ev
Page 61 and 62: me. But I was also lucky that when
Page 63 and 64: The tests indicated that the drops
Page 65 and 66: July 17, 1918. Czar Nicholas II, hi
Page 67 and 68: Guest list pared With the refusal o
Page 69 and 70: But only 18 of the states are hooke
Page 71: that to all felony offenses, as Ala

Investigating CSI – Background material Table of Contents I ...

Create successful ePaper yourself

Delete template?

Save as template?