Almost a century ago, it was discovered that human milk activates the coagulation system, but the milk component that triggers coagulation had until now been unidentified. In the present study, we identify this component and demonstrate that extracellular vesicles (EVs) present in normal human milk expose coagulant tissue factor (TF). This coagulant activity withstands digestive conditions, mimicking those of breastfed infants, but is sensitive to pasteurization of pooled donor milk, which is routinely used in neonatal intensive care units. In contrast to human milk, bovine milk, the basis of most infant formulas, lacks coagulant activity. Currently, the physiological function of TF-exposing vesicles in human milk is unknown, but we speculate that these vesicles may be protective for infants. Another explanation could be nipple skin damage, which occurs in most breastfeeding women. Milk-derived TF-exposing EVs may seal the wound and thereby reduce bleeding and breast inflammation.

A fingermark contains important forensic information of the donor, not only in its ridge pattern, but also in the chemical composition of its secretion. Detection and identification of these secretions can be done by immunolabeling. In this study, we describe for the first time a reproducible immunolabeling method that allows the simultaneous detection of multiple components of interest. This method not only reduces the manipulation of fingermarks, but also different types of information can be obtained about the donor in one labeling session. To prove the concept of this technique, we selected two general components as antigens of interest, dermcidin and the human serum albumin. Conjugation of both antibodies to two different synthetic fluorophores, followed by simultaneous incubation of both conjugated antibodies, resulted in successful multiple immunolabeling of fingermarks left on a porous nitrocellulose membrane and on a non-porous glass slide surface. In order to minimize false positives to prevent non-specific binding of antibodies to fingermarks and surface carriers, careful blocking and washing steps were found crucial. With this reproducible protocol, high quality images could be obtained from the multiple labeled fingermarks. In conclusion, simultaneous multiple immunolabeling of antibodies in fingermarks can identify specific components in the secretion of the fingermark, including components related to hygiene, diet, time of day, contacts gender and drug use. Multiple immunolabeling therefore has the potential to make a major impact in the forensic field.

Already for some decades lateral flow assays (LFAs) are ‘common use’ devices in our daily life. Also, for forensic use LFAs are developed, such as for the analysis of illicit drugs and DNA, but also for the detection of explosives and body fluid identification. Despite their advantages, including ease-of-use, LFAs are not yet frequently applied at a crime scene. This review describes (academic) developments of LFAs for forensic applications, focusing on biological and chemical applications, whereby the main advantages and disadvantages of LFAs for the different forensic applications are summarized. Additionally, a critical review is provided, discussing why LFAs are not frequently applied within the forensic field and highlighting the steps that are needed to bring LFAs to the forensic market.