Statement of Purpose, XX, Food Science PhD Thesis。这篇SOP写得较好，前半部分内容比后半部分的好。特别是后半部分呃逆荣，注意精炼语言。另外，需要注意一些细节上的处理方式。 The Motivation and Goal。Naturescience seems charming from my childhood, and I always eager to continue myacademic study in this field to turn out my interests and curiosities intorealities。

原文：

Statement of Purpose, XX, Food Science PhD / Thesis

In this essay I outline my academic accomplishments and discuss my careerambitions and the motivation to pursue the graduate program in Food Scienceat the University of XX.

The Motivation and Goal

Naturescience seems charming from my childhood, and I always eager to continue myacademic study in this field to turn out my interests and curiosities intorealities. My father is an ichthyologist. Even though I was a child, I havebeen allowed to access the laboratory where my father and his colleagues devotemost of time to epidemic and disease prevention of aquatic animals and securityof aquatic products.（切入点很好，建议将句子做精简）I still remember that interesting period: my father heldmy hand and taught me how to use a pipette, showed me the anatomy of differentfishes and picked me to the river bank to take samples. I was inspired by theirpassions on researching then I began desiring to be a biologist and became morecurious to learning Biology in my schooling.

Rightfrom my middle school days, I had chances to make more contact with the subjectof Biology. Biology allows me to explore deeper knowledge among the livingthings such as human being, animals, fungi and germs. At the high school level thoughI was exposed to only fundamentalconcepts of biology, but the introduction about cell, gene, deoxyribonucleicacid (DNA) and protein intrigued me a lot. Therefore, I usually questionedmyself as to why these molecules/components were important to organisms, howthese genetically engineered microorganisms can clean up the pollution areasand how the Polymerase Chain Reaction (PCR) technology can detect thedifference between two species. All these curiosity and achievements impelledme to pursue my career on biological sciences in the university.（内容顺畅，同上，语句做进一步精简）

Study and Research in University

Undergraduate

The undergraduate curriculum in Plant Protection at China University, introduced me to a wide-regionof subjects, both in and outside the field. Various courses like Food hygienicinspection, Molecular biology, Biochemistry, Microbiology and Botany haveprovided me broad background in the biological sciences andfood science. For the period of undergraduatestudy, I maintained an excellent GPA (85%) and obtained first-class ofscholarship.（建议将具体擅长及得分高的科目明确出来）

During the extra-curricular time from sophomore to senior years, I worked in Professorxx lab, applying molecular biology and biotechnology principles to study the Ribonucleic acid interference (RNAi) technology in biological control.Chitin-binding protein (CBP) is the important protein for insect to reconstructits body and peritrophic membrane. (Kramer K.J. et al. 1986) In my research, Plutella xylostella L. as the researchobject, I preliminary studied its cloning and sequence analysis by applying rapid-amplificationof cDNA ends (RACE) technology, reverse transcription-polymerase chain reaction(RT-PCR) technique and other basic molecular biology technologies and providedthe further information for developing RNAi technology on controlling Plutella xylostella L.（是否有发表论文及得出相关的研究结论或者发现需要深一步研究的问题，可以做一个说明）At the sametime, I finished my bachelor's degree thesis: Chitin-binding protein cloningand sequence analysis. This project not only provided me considerableexperiment experience including bacterial culture, gene cloning, DNA sequenceanalysis, expression of recombinant, and western blotting etc, but also taughtme how to plan an experiment, cooperate with group members and seek appropriatemethods to overcome a series of research problems.（建议与研究生阶段的学习做衔接，是内容看起来更为流畅饱满）

Graduate

After graduated from the university, I was recommended to the graduate school as a mastercandidate. At the post-graduate stage, I study and research in xx key laboratory of food quality and safety in XX University under the guide of Professor XX. Besides keeping outstandingGPA (88%) in graduate study, I participated in different kinds of researchprojects including: Surface display and bioactivity of Bombyx mori acetylcholinesterase (BmAChE) onPichia pastoris (P.pastoris),Codon optimization and surface display of BmAChEon P.pastoris, Codon optimization ofa DNA sequence of single chain Fv antibody against clenbuterol for expressionin P.pastoris, Affinity maturatin ofant-carbofuran single chain FV by site-directed mutagenesis, Construction andidentification of an anti-clenbuterol single-chain Fv libraryfor ribosome display.（注意这部分内容是否与简历上的内容重复，如果有重复，保留最重要的内容即可）

By involving in these projects, I had a deeper understandof the application of biotechnology in food science and learn a lot. First ofall, yeast surface display system is the outstanding display system that is ableto express various proteins through fusing to an anchor protein and expressedon the cell surface. Yeast display system has been utilized for a variety ofapplications, such as the construction of biosenser, protein evolution andbiorefinery applications (Tsutomu Tanaka et al. 2012). In ourproject, we broke through the traditional isolation that required an enzymepurification step generated a yeast surface display of AChE that can be used inefficient high-throughput screening methods for food residue detection.Secondly, codon optimization technology is the promising way solves the low expressionlevel of the recombinant proteins which is not allowed to be used in practicalapplications. In order to improve the expression level of clenbuterol (CBL) andsurface display level of BmAChE, weredesigned and synthesized the DNA sequence encoding based on the codon bias ofP. pastoris and improved theexpression level of CBL and surface display level of BmAChE significantly. Moreover, the Site-directed mutagenesis byhomology modeling and ribosome display technology are also the great ways toimprove the affinity and bioactivity of target protein.（最好写出在实验中你本人担任的角色，承担的主要工作内容及重要性，以及得到的成果结论）In the end, I had finishedthese projects and also co-authored several articles on PLoS ONE, AppliedMicrobiology and Biotechnology, Chemical Journal of Chinese Universities andJournal of Chinese Food Science.（明确文章题目及第几作者）The master program made me realize that the combinationof food science and biotechnology would have a glorious prospect and benefitthe community and society at large.（建议变化表达方式，使行文流畅）

The Reasons for pursuing a PhD Program in XX University

When I finish mymaster program, I decide go abroad to pursue PhD. I’m always thinking that the explorationof food sciences is not only interdisciplinary but also international.（建议变换句型，注意句型多样性）Besides the desire to learn more advanced technology, I hope to fuse the researchconcept with east and west. So I prefer to study abroad for advanced studiesafter my graduation. （内容比较空洞，建议具体说明MASTER阶段中没有学到的知识，以及研究不够深刻等）And win more academic accomplishment in the food science fulfillmy dream of standing on the foremost frontline in biology science. The XX University is "the" place I can accomplish my dream. For one reason, the XX University has the famous discipline--Food Sciences which attract me to learn and share in. For the other reason, myprevious research background matches the studying areas of the University alot. Therefore, I am more and more certain that I am well prepared for thefurther exploration into the respected program in XX University.Despite the highly competition of your admission, I still regard the researchprogram from as XX University my future goal.（可以提及申请大学提供的资源，以及自己打算怎么使用这些资源）

Ambitions and plans

If admitted tothe XX University, I will devote my enthusiasm and energy toadvancing my understanding of molecular biology and food science so that I candevelop innovative ideas, master new technical skills, and publish high-qualityresearch articles. I’m very confident that I will make a significant contribution to the graduate program at your university.（对于未来的计划写得太过简单，需要细化PHD阶段中具体学习安排，以及毕业后的打算）

I'm lookingforward to the opportunity of having an interview at your university.

TPO小站综合点评及批改意见：

总的来说，这篇SOP写得较好，前半部分内容比后半部分的好。特别是后半部分略微冗长，注意精炼语言。另外，需要注意一些细节上的处理方式。