Diatoms are eukaryotic, unicellular algae that belong to a Bacillariophyceae fam ily and it exists in water. Diatom is important in determining whether or not -
a person died as a result of drowning. When a corpse is retrieved from the water, it
is generally believed that the death was caused by drowning, and that the body was
drowned either before or afer death. In such circumstances, the existence of diatoms
in body tissues is a very useful evidence in determining the cause of death. Various
types of diatoms found in dead body tissues are related to the types of diatoms present
in bodies of water that are recovered from the body. Te objective of this study was
to fnd out which types of Diatom are present in different freshwater bodies around
Patna district of Bihar, India. In this research, freshwater samples were collected by
Random Sampling Technique from 17 different water habitats of Patna, during January to February, 2021. For diatom analysis, samples from ecological niches like river
Ganga, ponds, and lakes were collected in clean water bottles with tight-ftting caps.
Extraction of diatoms is done in two ways: Te H2O2 method and the HNO3 method.
Te aim is to determine which extraction procedure — H2O2 or NHO3 — is best for
diatom extraction. Afer the extraction of diatoms, the examination and photography
of diatoms species is performed by compound microscope (Leica DM750 with Leica
ICC50 E camera). Different Diatoms species found in various water environments at
different location were investigated in this research. Some of their names are Cymbella
sp., Fragiliaria sp., Ehrenbergiulva granulosa, Coscinodiscus radiates, Cyclotella sp.,
Melosira sp., Actinoptychus sp., Triceratium sp., Nietzsche sp., Actinocyclus sp. Te
information from this experiment will help in forensic science laboratories to identify
diatoms, criminal investigation and locating drowning sites or place of crime. In this
analysis we found that nitric acid digestion method give better extraction as compare
to hydrogen peroxide extraction method.