Actual sperm released from a substrate may be as low as ______ of sperm deposited in stain
10-15%Certain substrates, such as cotton, hold on to sperm better than others
What are the 2 techniques for generateing a DNA profile from stained slides?
1. xylene bath to remove coverslip/mounting mediua, tranfer bio material to extraction tube by scraping/swabbing2. laser capture microdissection
Who collects sexual assault kit samples?
ER doctorsMESANE nurses (Sexual Assualt Nurse Examiner)Most major hospitals
How long do Sexual Assault kits take to collect?
How long does it take to analyize a kit?
several hours to several months
How long are the kits retained?
Until the case has been adjudicateduntil statue of limitaions has expiredindefinietly in homicide casesmaybe discarded sooner if victims requests or if case isnt reported to police
What are the steps?
Control swabs Toxicology testing Known blood sample Oral swabs/smearsFingernail scrapingsForeign material collectionsclothing collectionsbitemarkshead/pubic hair combingshead/pubic hair standardsgenital,perianal, vaginal and anal swabs and smears
Why is time since intercourse important?
-When IDing the presence of semen isnt enough-a consensual partern may be a factor-sperm cells can be unrealted to assualt-aides in establishing time/circumstances of death
Typical post-coital interval (PCI)intact sperm in vagina
PCI sperm heads
PCI sperm heads in cervix
PCI P30 in vagina
PCI AP in vagina
Studies show that ____% of rapists do not ejaculate after _____ minuites of vaginal penetration
The vagina is a ___ enviornment
the cervix is a ______ environment
T/F Semen identified on anorectal swabs indiacts anal penetrationTrue False
FALSE:�Could be a result of contamination from vaginaldrainage �Could be due to collection technique wheninserting swabs into the rectum
What factors effect PCI?
Stage in menstrual cyclewashing/urinating/defacating/eatingMovementcollection techniquewashings, swabs, smears, liquid salivadeathtemp and humidity