The invention relates to a La-1-like peptide agent that increases sperm motility. It is non-toxic and it may be used to treat male infertility in humans, and also to increase fertility in animals. It may be used in artificial reproductive techniques such as in vitro fertilisation (IVF), including intra-cytoplasmic sperm injection (ICSI). The La-1 like peptide agent may also be used in artificial insemination techniques such as intra-cytoplasmic uterine injection (IUI).

The invention relates to a La-1-like peptide agent that increases sperm motility. It is non-toxic and it may be used to treat male infertility in humans, and also to increase fertility in animals. It may be used in artificial reproductive techniques such as in vitro fertilisation (IVF), including intra-cytoplasmic sperm injection (ICSI). The La-1 like peptide agent may also be used in artificial insemination techniques such as intra-cytoplasmic uterine injection (IUI).

Methods of determining whether a circulating tumor cell (CTC) marker, e.g., a CTC or fragment thereof, is present in a sample, such as a blood sample, are provided. Aspects of the methods include flow cytometrically assaying a fluorescently labeled sample that has been fluorescently labeled with a fluorescently labeled chlorotoxin binding member to determine whether a CTC marker is present in the sample. Also provided are compositions for practicing the methods. The methods and compositions find use in a variety of applications.