A comparison between two different dried blood substrates in determination of psychoactive substances in postmortem samples

Identification of Benzodiazepine Use Based on Dried Blood Stains Analysis

Biological matrices are typically used in forensic toxicological or pharmacological analysis: mainly blood, vitreous humor or urine. However, there are many cases in which crimes are a consequence of drug intoxication or drug abuse and they are not closed because over the months or years the samples become altered or decomposed. A dried blood stains test (DBS-MS) has recently been proposed to be used in drug toxicology when blood is found at a crime scene. This test could help an investigator to reveal what a person had consumed before the perpetration of the crime. In order to check the possibilities of this test, we analyzed several dried blood stains located on a cotton fabric. Therefore, the aim of this study was to determine if the analysis of a dried blood spot located on a cotton fabric could be an alternate source of obtaining toxicological results, particularly regarding benzodiazepines. We splashed blood stains on cotton fabric with different concentrations of the following benzodiazepines: alprazolam, bromazepam, clonazepam, diazepam and lorazepam, which were dried for 96 h and subsequently quantified by high-performance liquid chromatography coupled mass spectrometry (HPLC-MS). Our results show that it is possible to identify several benzodiazepines contained in a cotton fabric blood stain; consequently, this method may add another sample option to the toxicological analysis of biological vestiges found at a crime scene.

Stability of diazepam's phase II metabolites in dried blood spots on filter paper

Phase II metabolites play an important role in diazepam-related cases. The study aimed to assess the stability of diazepam's phase II metabolites in dried blood spots on filter paper.

METHODS

A piece of filter paper was spotted with 100 µL of whole blood (added 1% sodium fluoride as needed) obtained from participant who received 5 mg diazepam orally, air dried for 2 h at room temperature, and then stored at different conditions. Whole spots were cut at 0.1 cm from the outer edge of blood spots at post-consumption time-points of prior (zero), 5, 16, 35, 61, 120 days and 1, 1.5 years. Analytes were extracted with methanol/water mixture (8:2, v/v) and determined using HPLC-MS/MS. Decomposition rules were analyzed by a statistical software "SPSS".

RESULTS

Temazepam glucuronide remained stable (0.5-18.6% loss) at 20 ℃ and at 20 ℃ with 1% sodium fluoride for 16 days, while it was unstable after 5 days at 4 ℃ (21.1-26.2% loss) and - 20 ℃ (28.9 - 34.4% loss). After 35 days, temazepam glucuronide concentrations began to fluctuate significantly under all conditions, and an obvious increase (290.4-355.1%) was observed in 1.5 years. Oxazepam glucuronide was always unstable after 5 days, the percentage loss was even 100% when it was stored for 61 days and 1.5 years.

CONCLUSIONS

Dried blood spots on ordinary filter paper are recommended to be stored at 20 ℃ or 20 ℃ with 1% sodium fluoride within 16 days. Samples should be analyzed immediately or stored in sterile and dry media.

Revolutionizing Blood Collection: Innovations, Applications, and the Potential of Microsampling Technologies for Monitoring Metabolites and Lipids

Blood serves as the primary global biological matrix for health surveillance, disease diagnosis, and response to drug treatment, holding significant promise for personalized medicine. The diverse array of lipids and metabolites in the blood provides a snapshot of both physiological and pathological processes, with many routinely monitored during conventional wellness checks. The conventional method involves intravenous blood collection, extracting a few milliliters via venipuncture, a technique limited to clinical settings due to its dependence on trained personnel. Microsampling methods have evolved to be less invasive (collecting ≤150 µL of capillary blood), user-friendly (enabling self-collection), and suitable for remote collection in longitudinal studies. Dried blood spot (DBS), a pioneering microsampling technique, dominates clinical and research domains. Recent advancements in device technology address critical limitations of classical DBS, specifically variations in hematocrit and volume. This review presents a comprehensive overview of state-of-the-art microsampling devices, emphasizing their applications and potential for monitoring metabolites and lipids in blood. The scope extends to diverse areas, encompassing population studies, nutritional investigations, drug discovery, sports medicine, and multi-omics research.

Dried Blood Spots (DBS): A suitable alternative to using whole blood samples for diagnostic testing of visceral leishmaniasis in the post-elimination era

BACKGROUND

Serum or whole blood collection, processing, transport and storage still present significant challenges in low resource settings where mass surveillance is required to sustain disease elimination. Therefore, in this study, we explored the diagnostic efficacy of dried blood spots (DBS) as a minimally invasive and potentially cost-effective alternative sampling technique to whole blood sampling procedures for subsequent detection of Leishmania donovani antibodies or DNA.

METHODOLOGY AND PRINCIPAL FINDINGS

Archived serum, DNA samples from whole blood of visceral leishmaniasis (VL) cases and healthy controls, and DBS from corresponding cases and controls, were used. Both molecular and serological assays were optimized to detect L. donovani antibodies or DNA in DBS elute and results were compared against those obtained with whole blood. Serological assays (both rK28 ELISA and rK39 ELISA) of DBS samples showed sensitivity and specificity of 100% and had excellent agreement with results from whole blood samples (kappa value ranged from 0.98-1). Bland-Altman analysis of OD values from rK28-ELISA with DBS elute and patients' serum showed an excellent agreement (ICC = 0.9) whereas a good agreement (ICC = 0.8) was observed in the case of rK39-ELISA. However, qPCR and RPA of DBS samples had a diminished sensitivity of 76% and 68%, respectively, and poor agreement was observed with the whole blood samples.

CONCLUSION

Our results demonstrate that DBS offer excellent diagnostic efficiency for serological assays and represent a viable alternative to whole blood sampling procedures.

Emerging Microfluidic Devices for Sample Preparation of Undiluted Whole Blood to Enable the Detection of Biomarkers

Blood testing allows for diagnosis and monitoring of numerous conditions and illnesses; it forms an essential pillar of the health industry that continues to grow in market value. Due to the complex physical and biological nature of blood, samples must be carefully collected and prepared to obtain accurate and reliable analysis results with minimal background signal. Examples of common sample preparation steps include dilutions, plasma separation, cell lysis, and nucleic acid extraction and isolation, which are time-consuming and can introduce risks of sample cross-contamination or pathogen exposure to laboratory staff. Moreover, the reagents and equipment needed can be costly and difficult to obtain in point-of-care or resource-limited settings. Microfluidic devices can perform sample preparation steps in a simpler, faster, and more affordable manner. Devices can be carried to areas that are difficult to access or that do not have the resources necessary. Although many microfluidic devices have been developed in the last 5 years, few were designed for the use of undiluted whole blood as a starting point, which eliminates the need for blood dilution and minimizes blood sample preparation. This review will first provide a short summary on blood properties and blood samples typically used for analysis, before delving into innovative advances in microfluidic devices over the last 5 years that address the hurdles of blood sample preparation. The devices will be categorized by application and the type of blood sample used. The final section focuses on devices for the detection of intracellular nucleic acids, because these require more extensive sample preparation steps, and the challenges involved in adapting this technology and potential improvements are discussed.

Development and validation of an LC-MS/MS assay for the quantitative analysis of alprazolam, α-hydroxyalprazolam and hydrocodone in dried blood spots

Dried blood spot (DBS) has been used as an alternative matrix in drug testing. In forensic testing it offers enhanced stability of analytes and ease of storage that requires minimal space. This is compatible with long term archiving of large numbers of samples for future investigation. We employed liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify alprazolam, α-hydroxyalprazolam, and hydrocodone in a DBS sample that has been stored for 17 years. We achieved linear dynamic ranges (0.1-50 ng/mL) that capture wide ranges of concentration of the analytes below and above their reported reference ranges, and limits of detection (0.05 ng/mL) of 40-100X lower than the lower limit of the analyte's reference ranges. The method was validated according to FDA and CLSI guidelines and successfully confirmed and quantified alprazolam and α-hydroxyalprazolam in a forensic DBS sample.

Dried Blood Spot in Toxicology: Current Knowledge

Dried Blood Spot (DBS) is becoming very popular in various medical fields, especially in toxicology. Nowadays it is commonly used in newborn screening for inherited or congenital diseases. This paperwork is based on a review of available literature. DBS is simple and rapid, it does not require trained medical staff to collect the samples. Specimens can be easily and safely transported to the laboratory. DBS provides an opportunity for roadside testing and rather quick results. Venous blood spot, collected from a finger or a heel, is put on the special paper card, which can result in a different distribution of blood and concentration of detecting substances. Marking multiple substances from one spot is extremely challenging, but due to further advancements in this area, it is only a matter of time until it becomes possible and all the disadvantages vanish. DBS is certain to develop and become even more worldwide used.

Analysis of Cannabinoids and Metabolites in Dried Urine Spots (DUS)

Dried urine spots (DUS) represent a potential alternative sample storage for forensic toxicological analysis. The aim of the current study was to develop and validate a liquid chromatographic tandem mass spectrometric procedure for the detection and quantitative determination of cannabinoids and metabolites in DUS. A two-step extraction was performed on DUS and urine samples. An LC-MS/MS system was operated in multiple reaction monitoring and positive polarization mode. The method was checked for sensitivity, specificity, linearity, accuracy, precision, recovery, matrix effects and carryover. The method was applied to 70 urine samples collected from healthy volunteers and drug addicts undergoing withdrawal treatment. The method was successfully developed for DUS. LODs lower than 2.0 ng/mL were obtained for all the monitored substances. All the validation parameters fulfilled the acceptance criteria either for DUS or urine. Among the real samples, 45 cases provided positive results for at least one compound. A good quali-quantitative agreement was obtained between DUS and urine. A good stability of THC, THCCOOH and THCCOOH-gluc was observed after a 24 h storage, in contrast to previously published results. DUS seems to provide a good alternative storage condition for urine that should be checked for the presence of cannabinoids and metabolites.