Discovering miR-133a-5p: A Quick Way to Estimate Time of Death

When a body is found at a crime scene, figuring out how long it's been there is super important for solving the case. Scientists are looking at tiny bits of genetic material called microRNAs (miRNAs) that stay stable even after death. This study used a special tool called a molecular beacon probe to detect a type of miRNA called mmu-miR-133a-5p in mouse muscle tissue. They wanted to see if this probe could help estimate the postmortem interval (PMI), which is the time between death and discovery of the body. The scientists designed the probe to change shape when it found mmu-miR-133a-5p. This change made the probe give off a strong light signal. They tested this probe on mice that had been left at two different temperatures, 4°C and 21°C, for up to 10 days. The probe could detect very small amounts of mmu-miR-133a-5p, and the amount of light it gave off was related to how much mmu-miR-133a-5p was present. Even after 10 days, the probe could still find the miRNA in the mice's muscles. This new method is quick and easy to use, taking only 30 minutes after extracting the genetic material. It could be used right at the crime scene, making it simpler to estimate the time of death. This could help investigators solve cases faster.