Sample collection and preservation of biological samples
- 1. Sample Collection And Preservation Of Biological Samples Submitted by: Neha Agarwal M.Sc. Forensic Science LNJN NICFS
- 2. General directions Packing and Labeling I. Each particle should be separately packed II. Serial numbers should be mentioned III. Labels should be numbered consecutively IV. Should bears the signature of forwarding officer along with the date and other required details. V. Labels must not be pasted on weapons or instruments, suspected to contain stains.
- 3. Sealing I. All parcels should be sealed by dispatching officers and packed in such a manner that they cannot be opened without destroying the seal II. Impressions of keys, coins, metal, button, weights etc must not be used as seal Chain Of Custody Of Exhibits I. Chain of custody must be maintained to maintain the integrity. II. Record must be maintained of the persons through whom exhibits passed and to whom they were delivered together with the time and date of such receipt and delivery
- 4. Forwarding I. A forwarding letter must be enclosed in the parcel so that the connection of exhibit with the relevant cases is maintained. II. Forwarding letter should contain following particulars: Report Number Case Reference Brief History Of Case Description Of Each Articles In Parcel Nature Of Examination Required Forwarding Note Of The Officer Name Of I.O. Facsimile Of The Seal Used Certificate Of Authority To Examine
- 6. Types of Crime Exhibits • Blood/ Blood stains • Semen/ Semen stains • Saliva stains • Hair • Bone • Flesh
- 7. • All the samples should be collected by wearing hand gloves with all the precautions being taken to avoid any contamination of the specimens. • The samples should be labelled with information including type of specimen, (e.g. Blood/urine/vaginal swab/anal swab etc.), case number, name, age and sex of the patient, date of collection, site of collection, name of concerned police official and name with designation of the doctor.
- 8. • Blood samples collected by the doctors during MLC or Post-mortem should be preferred on gauze cloth piece thoroughly dried in shade not in direct sunlight and packed in paper or cloth. • The blood samples should never be packed in damp/wet conditions and never be packed in polythene/plastic Container/ Air-tight Container.
- 10. Condition Of Sample Location Collection Clot Scene/hospital Use syringe to collect into EDTA tubes or on gauze or cotton. Transfer onto cotton cloth & Air dry. Liquid Scene Collect clot in test tube & add equal volume of saline. Transfer onto cotton cloth & air dry. Wet Clothing Air dry at room temperature & package in a paper bag. Also avoid direct heat/ ironing to dry the stains as heat destroys the samples. Do not accelerate drying and take care to avoid contamination. Wet object Air dry at room temperature transfer the stain on gauze air dry and pack in the cotton cloth or envelope paper.
- 11. Condition Of Sample Location Collection Crusts Small Object Scratch crust into paper packet. Collect control blank stains Weapon of offence Collect item directly. Should be packed separately in boxes with stained areas covered by paper stains Large Object Collect entire item, if it is smaller one. For the larger object transfer the stain on gauze soaked in saline and air dry. stains Upholstery ,Carpet Wallpaper .Wood Cut out stained area. Package separately. Collect control. stains Unmovable surface Concrete wall Do not scrape collected by swabbing. double swab method involves applying a moistened cotton swab followed by a second dry cotton swab onto the same target surface of evidence. The target surface is swabbed using a moistened swab first. The moisture left by the first swab is absorbed by the second dry swab.
- 13. A cigarette butt as a source of DNA evidence. Shed cells left behind on a cigarette butt can be a source of DNA.
- 14. Semen
- 15. Condition Of Sample Location Collection liquid Victim Collect sample with swabs and should be air dried and packed in paper envelopes. Smear preparation on slide is more suitable than swab for sperm examination. Reference samples of victim and accused must be taken. stain Victim Collect sample with swabs and should be air dried and packed in paper envelopes instead of Airtight Plastic container liquid Scene Transfer on to cotton cloth. Air dry. wet Clothing Air dry at room temperature and package in a paper bag. Avoid direct heat /ironing to dry the stains as heat destroys the samples. Do not accelerate drying and take care to avoid contamination
- 16. Saliva
- 17. Condition Of Sample Location Collection objects Cigarette Completely dry cigarette ends and pack separately in paper bag or envelope. Store in a cool, dry environment stain Clothing Completely dry cigarette ends and pack separately in paper bag or envelope. Store in a cool, dry environment objects Cups or glasses Should be sent after drying and wrapping it with paper.
- 18. Hair
- 19. Condition Of Sample Location Collection With tissue Scene Collect hair with tissue in container & Keep refrigerated With blood Scene Air dry. Collect in a paper packet. Person Samples of hair complete with roots should be taken. Collect in a paper packet.
- 21. Location Collection Hospital Tissue samples and Foetus should be stored in normal saline. Formalin should never be used as preservative. Glass container should not be used. Blood sample of the mother should be sent along with Foetus
- 22. Bones/ teeth
- 23. Location Collection Hospital Air Dried at room temperature. Seal the items in suitable cloth or paper.
- 25. Sample Location Collection Vomit Hospital/scene Should be collected in chemically clean glass covered containers. In case of dried stain, moisten the stain with distilled water. Collect moistened stain with foam tipped swab/ gauze piece and air dry. Pack this dried swab in paper envelope. Collect swabs of different spots in different packets/ envelopes. Stool Hospital/scene Should be collected in chemically clean glass covered containers. Stomach Wash Hospital Stomach should be ligated on both ends and dissected out. Then the greater curvature should be opened up so that the contents directly pour onto a wide mouth glass bottle Residual Food Scene Should be collected in chemically clean glass covered containers. Cooking utensils, empty containers and the containers of the residual food should also be collected.
- 26. DO’S AND DON’TS • Parcels/packets should be mentioned properly on Forwarding letter and Road certificate with respect to their serial No., Seal impression, contents and source of exhibits. • Parcels/packets should be marked (i.e. serial No., FIR, U/S, P.S., MLC No., P.M. No. etc.). • Parcels/packets should be properly sealed. • Seal impressions should be legible / complete on parcels/packets. • Sample/specimen seal should be attached/legible/complete/matching with that on parcels/packets. • Sample/specimen seal should be attested by I.O. / S.H.O / Medico Legal Officer and case information (FIR, U/s, P.S., MLC No. P.M. No etc.) should be written. • Parcel/packets must be signed by I.O./concerned doctor etc. • Attested photocopies of FIR/D.D. entry/seizure memo/MLC/P.M. report should be enclosed. • Forwarding letter/certificate should be complete (Containing memo No. and case information) and attested by the forwarding authority. • Nature of examination should be clear/proper and without overwriting/cutting/ correction. • Overwriting/cutting/correction is/are must be signed by forwarding authority. • The cases are submitted from 10.00 a.m. to 1.00 p.m. and reports can be received from 02.00 p.m. to 5.00 p.m. • Separate forwarding letters, Road certificate and other relevant papers should be prepared for Different Divisions for submitting cases and receiving reports. • INVESTIGATING OFFICERS SHOULD DEPOSIT EXHIBITS OF ALL CASES FOR EXAMINATION WITHIN 7 DAYS FROM THE DATE OF ITS COLLECTION.
- 27. Thank you