**4.7. Magnetic immunoassay (MIA)**

The magnetic nanoparticles were discovered by Frenchman Louis Néel, and he got the first Nobel Prize in Physics in 1970. The scientists described the superparamagnetic quality of these magnetic nanoparticles in the magnetic field. These component magnetic nanoparticles are in the range of 5–50 nm while the magnetic beads may be in the range of 35 nm–4.5 μm. A novel type of diagnostic immunoassay was developed by using these magnetic beads as labels. The presence of magnetic labels is measured by the magnetic reader, that is, magnetometer. Therefore, the signals measured by the instrument are directly proportional to the analyte in the serum (toxin, cardiac marker, virus, bacteria). The superparamagnetic quality of these beads has already been in practice in magnetic resonance imaging (MRI) [52].

**5. Aptamers**

therapeutics and diagnosis [56].

\*, Haleema Sadia2

\*Address all correspondence to: kausarbasit786@yahoo.com

Technology, Engineering and Mangement Sciences, Lahore, Pakistan

**Author details**

Kausar Malik<sup>1</sup>

Pakistan

**References**

205-213

30. Ithaca, NY: ISAAA; 2003

of Commercialized Biotech/GM Crops; 2004

Aptamers are single-stranded oligonucleotides of DNA or RNA molecules, and have property to bind with high affinity and specificity to their target due to their strong interactions and nanosize, respectively. This property of aptamers can be used for a number of applications in biomedical research, their high efficiency of molecular recognition makes them effective biosensors and therefore, they can be used to develop assays against different targets [55]. Different aptamers can be synthesized for a specific target through a process called systematic evolution of ligands by exponential enrichment (SELEX). Biosensing property of aptamers offers fast and easy detection of target molecules. This property can be used for diagnosis and other biomedical applications, which will help to fight against a number of diseases, including AIDS, cancer, Alzheimer's, viral and bacterial infections. A number of aptamers can be identified against various targets, including nucleotides, proteins, lipids, signaling molecules and even whole cells and microorganisms. Recent advances in research have proven that RNA aptamers have high therapeutic and diagnostic value. It can also be used for therapeutic delivery of oligos. All these attributes of aptamers make them pivotal tools of the emerging bionanotechnology and biosensors. Some research groups are working on aptamer technology and using them as aptasensors but it requires more attention to boost our research for diagnosis and fight against different diseases. Aptamers are easy to synthesize and more stable as compared to antibodies; therefore, they can be helpful in our future advances in

Protein-Based Detection Methods for Genetically Modified Crops

http://dx.doi.org/10.5772/intechopen.75520

61

and Muhammad Hamza Basit<sup>1</sup>

1 National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore,

2 Department of Biotechnology and Informatics, Balochistan University of Information

[1] Dunwell JM. Novel food products from genetically modified crop plants: methods and future prospects. International Journal of Food Science and Technology. 1998;**33**(3):

[2] James C. Preview: Global status of commercialized transgenic crops: ISAAA briefs No.

[3] Matsuoka T, Kuribara H, Akiyama H, Miura H, Goda Y, James C. Preview: Global Status
