Determination of the age of bloodstains using immunoelectrophoresis.

The technique of immunoelectrophoresis was used to determine the age of bloodstains. The immunoelectrophoretic patterns (IEP) of bloodstains ranging from 15 days to one year old were obtained by the use of high titer anti-whole human serum. The IEPs revealed gradual disappearance of beta-globulins and gamma-globulin with increase in the age of bloodstains. A comparative study of the IEP of normal human serum with those of the experimental bloodstains showed the absence of some of the corresponding proteins. The absence of a particular serum protein in the IEP of a given bloodstain will indicate the age of that bloodstain.     

Gc in bloodstains

Gc-subtyping was carried out on blood stains that had been made on cotton and glass and stored under a variety of conditions ranging from -20 degrees to +56 degrees C. The limits of detection ranged from 2 weeks at 56 degrees C up to 92 weeks at +4 degrees C and greater than 116 weeks at -20 degrees C. Additional bands that have been reported in other studies could not be detected during this study, and this difference is thought to be due to storage of the samples in the liquid state.     

Forensic determination of pregnancy hormones in human bloodstains.

When different bloodstains are encountered at the scene of crime, it is possible to discriminate those from a pregnant woman from others. Human chorionic gonadotrophin, human placental lactogen, total oestriol and progesterone in the stains may be determined with radioimmunoassay techniques using commercial kits. Only 1 cm2 of bloodstain is needed for the determination of all four parameters, which gives information about the state of pregnancy. More than 100 stains of blood from women in all stages of pregnancy, normal menstruating women, menopausal and post-menopausal women and male subjects, and of menstrual blood were analysed. Bloodstains from pregnant women were easy to evaluate with the four determinations, only very early pregnancies being undetected. Stains from non-pregnant women were negative or below the cut-off level. Two case examples are also described.     

Effects of luminol on the subsequent analysis of bloodstains.

The effects of luminol upon additional presumptive chemical tests, subsequent confirmatory blood tests, species determination by immunoelectrophoresis, ABO typing by absorption elution, and genetic marker analysis by multienzyme system electrophoresis were examined. Results indicate that luminol does not affect additional presumptive chemical tests, confirmatory tests, species determination, or ABO typing, but does affect certain genetic marker systems.     

Transferrin subtyping of human bloodstains

A method was described for subtyping transferrin derived from human bloodstains. Bloodstain cuttings were extracted in 0.5% ferrous ammonium sulfate. The extracts were subjected to ultrathin-layer polyacrylamide gel isoelectric focusing. After isoelectric focusing, transferrin was detected by silver staining. This method permitted the successful typing of Tf in 6-month-old blood stains maintained at -20 degrees C and room temperature and 3-month-old bloodstains maintained at 37 degrees C.     

Remote spectroscopic identification of bloodstains

Blood detection and identification at crime scenes are crucial for harvesting forensic evidence. Unfortunately, most tests for the identification of blood are destructive and time consuming. We present a fast and nondestructive identification test for blood, using noncontact reflectance spectroscopy. We fitted reflectance spectra of 40 bloodstains and 35 nonbloodstains deposited on white cotton with spectroscopic features of the main compounds of blood. Each bloodstain was measured 30 times to account for aging effects. The outcome of the blood measurements was compared with the reflectance of blood-mimicking stains and various body fluids. We found that discrimination between blood and nonblood deposited on white cotton is possible with a specificity of 100% and a sensitivity of 98%. In conclusion, a goodness of fit between the sample's reflectance and the blood component fit may allow identification of blood at crime scenes by remote spectroscopy.     

Phosphoglucomutase (PGM) grouping of bloodstains on silver.

This paper describes a case involving alteration of phosphoglucomutase (PGM) isoenzyme patterns in bloodstains present on silver. The effect could be produced by treating blood samples with silver nitrate solution.     

SEM analysis of red blood cells in aged human bloodstains.

Mammal red blood cells (RBC) in bloodstains have been previously detected by light microscopy on stone tools from as early as 100,000 +/- 25,000 years ago. In order to evaluate the degree of morphological preservation of erythrocytes in bloodstains, an accidental human blood smear on white chert and several experimental bloodstains on hard substrates (the same stone-white chert; another type of stone-graywacke; a non-stone support-stainless steel), were stored in a room, in non-sterile and fluctuating conditions, for lengths of time ranging from 3 to 18 months. Afterwards, the specimens were coated with gold and examined by a Cambridge Stereoscan 120 scanning electron microscope. Results revealed a high preservation of RBC integrity, with the maintenance of several discocytary shapes, a low tendency to echinocytosis and a frequent appearance of a moon-like erythrocytary shape in the thinner areas of the bloodstains.     

An improved method for subtyping Pi in old bloodstains.

Immunofixation procedures were used for detecting alpha-1 antitrypsin protease inhibitor (Pi) phenotypes in bloodstains. Neuraminidase elution of bloodstains, together with isoelectric focusing, immunofixation, and silver staining techniques, makes possible Pi subtyping in old bloodstains. No extra bands appear when the storage time is no longer than three months.     

紫外可见漫反射光谱法无损确证血痕的研究

目的建立一种快速确定血痕的方法。方法将人血、猪血、鸡血、羊血等制成样品纱布,利用紫外可见分光光度计扫描反射光谱进行检测,同时考察了人血的最低检出量。结果血痕的种属与浓度不影响紫外可见反射光谱波峰波谷位置;人血的最低检出量为1.0μL。结论该方法确证血痕具有快速、灵敏、准确、不损坏检材的特点。     

Transferrin subtyping of bloodstains and semen using isoelectric focusing and immunoblotting.

Transferrin (TF) subtyping was carried out on bloodstains that had been made on cotton sheeting and stored under a variety of conditions ranging from -20 degrees C to +37 degrees C. The time limit of detection was longer than 54 weeks after dry storage under each condition. Moreover the correlation between isoprotein types of the TF in blood and semen samples from the same individual was determined in 103 men. All three TF common types and two rare types in all semen samples correlated with the type found in the corresponding blood sample. A combination of isoelectric focusing separation and immuno-enzyme-linked detection may prove to be very useful for forensic TF subtyping.