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C H A P T E R 7 Latent Print Development 7.14.5 1,2-Indanedione 0.25 g 1,2-indanedione dissolved in 90 mL ethyl acetate and 10 mL glacial acetic acid. Add this to 1 L of HFE 7100 (Merrick et al., 2002, pp 595–605). or 2 g 1,2-indanedione dissolved in 70 mL ethyl acetate. Add this to 1 L HFE 7100 (Almog et al., 1999, pp 114–118). 7.14.6 5-Methylthioninhydrin (5-MTN) (Wallace-Kunkel et al., 2006, pp 4–13) 1.7 g 5-MTN dissolved in 52.5 mL ethyl acetate, 50 mL methyl tert-butyl ether, 12.5 mL absolute ethanol, and 5 mL glacial acetic acid. Add this to 360 mL HFE 7100. 7.14.7 2-Isononylninhydrin (INON, Thermanin) (Al Mandhri and Khanmy-Vital, 2005) 4–5 g INON dissolved in 15 mL ethyl acetate, 5 mL isopropanol, and 980 mL HFE 7100. 7.14.8 Silver Nitrate (Trozzi et al., 2000, pp 38–39) Dissolve 30 g silver nitrate in 1 L distilled water. or Dissolve 30 g silver nitrate in 100 mL distilled water and add to 1 L ethanol. 7.14.9 Physical Developer (Kent, 1998) Acid Pretreatment: 30 g of maleic acid is dissolved in 1 L distilled water. Indefinite shelf life. Stock Solution #1: 30 g ferric nitrate nonahydrate dissolved in 900 mL distilled water. 80 g ferrous ammonium sulfate hexahydrate dissolved in this solution. 20 g anhydrous citric acid dissolved in this solution. Shelf life may be several months. Stock Solution #2: 4 g n-Dodecylamine acetate dissolved in 1 L distilled water. 4 g (4 mL) Synperonic N added to this solution. Indefinite shelf life. Stock Solution #3: 20 g silver nitrate dissolved in 100 mL distilled water. Indefinite shelf life. 7–54 Working Solution: 900 mL stock solution #1. Add 40 mL of stock solution #2 and stir for 5 minutes. Add 50 mL of stock solution #3 and stir for 5 minutes. Shelf life is 1–2 weeks. Hypochlorite Post-Treatment Solution: 100 mL of household chlorine bleach (~6% NaOCl) is mixed with 100 mL water. 7.14.10 Multimetal Deposition (Saunders, 1989, 1996, 1997) Colloidal Gold Solution Stock Solution #1: 10% (w/v) tetrachlorauric acid (HAuCl .3H O) in high-purity (RO/DI) water. 4 2 Stock Solution #2: 1% (w/v) trisodium citrate (Na Cit.2H O) 3 2 in high-purity water. Stock Solution #3: 0.5 M (10.5% w/v) citric acid (H Cit.H O) 3 2 in high-purity water. Stock Solution #4: 1% Polyethylene glycol. Working Solution: Add 1 mL of stock solution #1 to 1 L of high-purity water and bring to a boil. Rapidly add 10 mL of stock solution #2 and boil gently for 10 minutes. Add 5 mL of Tween 20 (or Tween 80) and mix well. Add 10 mL of stock solution #4 to the cooled solution and adjust the pH to 2.7 using stock solution #3. Restore total volume to 1 L with high-purity water. Shelf life is 3 months. Modified Silver Physical Developer Solution Stock Solution #1: Dissolve 33 g ferric nitrate nonahydrate in 1 L of high-purity water. Add 89 g of ferrous ammonium sulfate hexahydrate to the solution. Add 22 g of citric acid to the solution. Add 1 mL of Tween 20 to the solution. Stock Solution #2: 20% (w/v) silver nitrate in high-purity water. Working Solution: Add 1 part of stock solution #2 to 99 parts of stock solution #1. Only stable for 15 minutes. Application Prewashing: Porous items should be washed several times in high-purity water.
Colloidal Gold: Soak items in colloidal gold solution for 30–120 minutes, but avoid overdevelopment. In-Between Rinsing: Rinse items in high-purity water. For porous items, use several water changes for 15 minutes or more. Silver Physical Developer: Place items into freshly made solution. Silver amplification occurs within 10–15 minutes. Postwashing: Rinse with tap water. Air dry. 7.14.11 MMD II (Schnetz and Margot, 2001, pp 21–28) Silanization of Glassware Soak glassware for 8 hours in 10% Extran MA 01 alkaline liquid (Merck). Rinse with high-purity hot water, then highpurity cold water. Dry in an oven at 100 °C. Soak for 5 seconds in 2% (v/v) 3-aminopropyltriethoxysilane in acetone. Rinse twice with acetone, then water. Dry in an oven at 42 °C for 8 hours. Colloidal Gold Solution Stock Solution #1: 10% (w/v) tetrachlorauric acid in highpurity water. Stock Solution #2: 1% (w/v) sodium citrate in high-purity water. Stock Solution #3: 0.5 M citric acid in high-purity water. Stock Solution #4: 1% (w/v) tannic acid in high-purity water. Working Solution #1: Add 0.5 mL of stock solution #1 to 400 mL of high-purity water. Heat to 60 °C. Working Solution #2: Add 20 mL of stock solution #2 and 0.1 mL of stock solution #4 to 75 mL of high-purity water. Heat to 60 °C. Once both solutions reach 60 °C, rapidly add working solution #2 to working solution #1 and mix vigorously. Heat the mixture to boiling, cool, and adjust to 500 mL with highpurity water. Solution can be stored in a plastic bottle at 4 °C. Before use, bring to room temperature, add 0.5 mL Tween 20 (or Tween 80), and adjust pH to 2.7 with stock solution #3. Silver Physical Developer Solution Stock Solution #1: 24 parts 25.5% (w/v) citric acid solution, 22 parts 23.5% sodium citrate solution, and 50 parts high-purity water. Adjust to pH 3.8 with additional citric acid or sodium citrate solution. Stock Solution #2: 0.2% (w/v) silver acetate solution. Stock Solution #3: 0.5% (w/v) hydroquinone in stock solution #1. Rinsing Solution: 0.25% (w/v) hydroquinone (1 part stock solution #3 and 1 part high-purity water). Working Solution: One part stock solution #2 and one part stock solution #3. Unstable, so prepare just before use. Application Prewashing: Porous items should be washed with high-purity water for 2 minutes. Nonporous items need only brief washing in high-purity water. Colloidal Gold: Soak items in colloidal gold solution for 5–15 minutes with mild agitation. In-Between Rinsing: Rinse briefly in high-purity water. In-Between Hydroquinone Rinsing: Rinse for 2–5 minutes in hydroquinone rinsing solution. Silver Physical Development: Place items in silver physical developer for about 18 minutes. Postwashing: Rinse with high-purity water. Fixing: Fix with 1:9 dilution of photographic fixer for 2–5 minutes, rinse with tap water, air dry. 7.15 Reviewers The reviewers critiquing this chapter were Christophe Champod, Sue Manci Coppejans, Christine L. Craig, Robert J. Garrett, Deborah Leben, Bridget Lewis, Jon T. Stimac, Juliet H. Wood, and Rodolfo R. Zamora. 7.16 References Latent Print Development C H A P T E R 7 Abderhalden, E.; Schmidt, H. Utilization of Triketohydrindene Hydrate for the Detection of Proteins and Their Cleavage Products. Z. Physiologische Chem. 1911, 72, 37. 7–55
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