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Technology Transfer Workshop Laser Microdissection Advanced LMD Forensic Applications Patrick Wojtkiewicz, Ph.D. North Louisiana Crime Lab (318) 227-2889.

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Presentation on theme: "Technology Transfer Workshop Laser Microdissection Advanced LMD Forensic Applications Patrick Wojtkiewicz, Ph.D. North Louisiana Crime Lab (318) 227-2889."— Presentation transcript:

1 Technology Transfer Workshop Laser Microdissection Advanced LMD Forensic Applications Patrick Wojtkiewicz, Ph.D. North Louisiana Crime Lab (318)

2 Technology Transfer Workshop LMD Strengths Microscopic identification of cells increases sensitivity & minimizes handling Easily separates Sperm and Epithelial DNA Quantification is done by cell counting Fluorescent attachment provides new capabilitie

3 Technology Transfer Workshop Fluorescent Capabilities Adds Capabilities for Analysis of All Types of Sexual Assault Evidence –Provide Improved Capabilities in Sperm Identification –Enable New Capabilities of Identifying Male and Female Diploid Cell Mixtures These procedures are in the development stage but have been successfully performed on actual case evidence (non-probative)!

4 Technology Transfer Workshop Sperm Identification Problems Few spermatozoa –Searches are often labor intensive –Analyst uncertainty about ID –Case processing based upon sperm id Excessive quantity of epithelial cells –Spermatozoa buried under cells –Combined with few spermatozoa Low quality microscope Poor staining

5 Technology Transfer Workshop Sperm Labeling by Fluorescent Dyes Based upon antibodies conjugated to AlexaFluor. Antibodies are specific to human sperm components. Easier, faster, and confident searches Backwards compatible (not LMD) Adds extra step in analysis Requires high quality microscope with fluorescence capabilities

6 Technology Transfer Workshop Sperm Paint Antibodies to:. –ESP (equatorial segment) –SP-10 (acrosomal protein) * –CaBYR-A (tail) Procedure –Add antibodies to smear 4ºC –Wash with H 2 O –Examine

7 Technology Transfer Workshop Fluorescent Sperm Identification Advantages –Simple procedure & Sequential processing of samples –Antibodies should not adversely affect DNA analysis –Samples can be examined at lower magnification Improved capability - Fast examination & confidence in negative results. Can be done on older slides. Previous slides are from casework-like material

8 Technology Transfer Workshop Problems in Diploid Cell Mixtures Sample may not be identified as a mixture prior to analysis. Mixture may not be apparent when there is a preponderance of DNA from one of the donors. Interpretation issues No current way of separating diploid cell mixtures.

9 Technology Transfer Workshop Chromosome Paint Fluorescent in situ hybridization (FISH) –X and Y chromosomes –commercial kit Interphase nuclei New capability of analyzing male & female epithelial cell mixtures Time & reproducibility Lymphocytes

10 Technology Transfer Workshop Buccal Cells from Swab

11 Technology Transfer Workshop Diploid cells Microdissection

12 Technology Transfer Workshop Concern About Y STR Results

13 Technology Transfer Workshop Extreme Cell Mixtures Female: Male Ratio # of loci in male profile # of loci in female profile 99: : : : : : :99102

14 Technology Transfer Workshop Real Case Results Identification and dissection of spermatozoa well established Following results based upon diploid cell analysis 40% of cases had at least one sample with enough diploid cells to obtain a male profile –Vaginal swab –Bitemark –Fingernail scraping

15 Technology Transfer Workshop Case #1 Fingernail Scrapings Item/LocusVictimFingernail Scrapings Vaginal SwabSuspect Known30 Female Cells 15 Male Cells25 Male Cells (Non-sperm) Known D3S135814, ,16 vWA16, ,18 FGA23,24 ND19,25 AMELXXYXY D8S117913, ,(15),16,(17)13,16 D21S1129,31.2 ND30,31 D18S5114,17 ND14.2,16 D5S8188, ,14 D13S31712 ND(8),11,1211,12 D7S8208,12888,9 D16S53910 ND99 THO19998,9 TPOX88ND10,11 CSF1PO11, ,12 D2S133818,23 ND18,25 D19S43312, ,16.2

16 Technology Transfer Workshop Case #2 Vaginal Swabs VICTIMVAGINAL SWAB SUSPECT KNOWN20 MALE CELLSACTUAL EVIDKNOWN D3S135814,1617,1814,16,17,1817,18 vWA14,1717,1814,17,1817,18 FGA19,21ND19,21,23,2523,25 AMELXXY D8S117911,1312,1311,12,1312,13 D21S ,3029 D18S5114,17ND13 D5S81811,121211,1212 D13S3178,12118,11,1211 D7S8208,12ND8,12 D16S ,(12)11,12 THO16,9.37,(9.3)6,7,9.36,7 TPOX8,11118,11 CSF1PO9,10119,10,1111 D2S133817,232517,18,23,2518,25 D19S ,14

17 Technology Transfer Workshop Case #3 Bitemark Swabs ITEM/LOCUSVICTIMVAGINAL SWABBITEMARK SWAB SUSPECT KNOWN30 FEMALE CELLS7 MALE CELLSACTUALKNOWN D3S135814,151415,1614,15,1615,16 vWA16, ,17,1816,18 FGA23,242419ND19,25 AMELXXNDXY D8S117913,14 ND13,14,1613,16 D21S1129,31.2ND 29,30,3130,31 D18S5114,17ND 14.2,16 D5S8188,128ND12,14 D13S31712ND11ND11,12 D7S8208,12 ND 8,9 D16S THO1998,9 TPOX88ND8,10,1110,11 CSF1PO11,12ND11,12ND11,12 D2S133818,23ND25ND18,25 D19S43312, ,14,14.2, ,16.2

18 Technology Transfer Workshop CODIS Searches In these cases, and other non- probative samples, the profiles were searched locally against approximately 1500 samples. In each case the partial profiles obtained by LMD only hit one sample, the correct one.

19 Technology Transfer Workshop Acknowledgements Jennifer Valentine Kelli Raley North Louisiana Crime Lab LSUSHSC


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