from typing import Dict


def find_essential_fields(biosample: Dict) -> bool:
    """
    check whether the essential field(s) exist in the sample record
    currently, essential field list only includes Material
    :param biosample: sample record
    :return: true if all essential fields are found
    """
    essential_fields = ['Material']
    for essential in essential_fields:
        if essential not in biosample['characteristics']:
            return False
    return True