This document summarizes a student's placement experience at Source Bioscience, a company that provides genomic services including DNA sequencing, microarray analysis, and testing for STIs. The student's role was as a Trainee DNA Sequencing Scientist, where they prepared and sequenced DNA samples using Sanger sequencing. Sanger sequencing involves making copies of a DNA region using DNA polymerase, primers, nucleotides, and chain terminators to determine the base pair sequence. The student gained experience with accurate pipetting, meeting turnaround times, customer contact, data interpretation, and teamwork. They provided examples of sequencing runs that were successful and unsuccessful. In conclusion, the student thanks the listener and offers to answer any questions about

1. My Placement
Year
Simran Bhardwaj
Human Biology
Year 3 (Placement)

2. Source Bioscience
Source Bioscience is a multidisciplinary biological company that plays a
fundamental role in the work of both genomics and clinical diagnostics. They
are the ‘Global Leader of Genomic Services’ and offer a extensive portfolio of
genomic services, on a variety of platforms.
The extensive equipment has capabilities including;
 Sanger sequencing
 Next generation sequencing
 Microarray analysis
 Genotyping
 And bioinformatics
There are also labs carrying out testing for STIs and PGS (pre genetic
screening) which examines the number of chromosome of embryos at the
early stages of division and flag any abnormalities.

3. My role
My role whilst on placement was a ‘Trainee DNA
Sequencing Scientist.’
•Prepare and sequence DNA samples
•PCR products or Plasmids
• Determine base pairs of DNA strands to
determine any mutations or abnormalities

4. Background of Sanger Sequencing
Sanger Sequencing is a chain termination method originally developed by
Fred Sanger in 1977. Regions of DNA of anywhere up to 1200 BP can be
sequenced and specific base pair sequences can be established.
This process involves making copies of a desired region of the DNA strand and
uses the following;
 DNA Polymerase
 Primer
 4 DNA nucleotides (dATP, dTTP, dCTP, dGTP)
 Template DNA
 And a dideoxy (chain terminator) which is dye labelled
with a different colour on each of the 4 nucleotides

5. Process of Sanger Sequencing
• Process DNA
• PCR (Denaturing, Annealing, Extension)
• Sephadex Cleanup
• Sequence on ABI 3730 analyser
• Analysis of data

6. Sequencing that
worked well
Between 1200-1300 BP long and
has strong calling. The more of
the area that has blue bars, the
analyser can call the nucleotide
with more confidence.
Analysis shows good
clean peaks so is
therefore confident in
calling each individual
base.

7. Sequencing that
failed
Messy overlapping peaks may be
caused by;
• Background noise/signals
• Possible contamination
• Multiple primer binding sites
This particular sample had a very weak and uncertain calling as the
bases could not be properly identified.

8. What experience I gained over
placement
• Accurate pipetting
• Ability to time keep
• Meeting strict turnaround times
• Customer contact
• Professionalism
• Work under pressure
• Data interpretation
• Team work

9. Opportunities to lead

10. On the Job Training

11. Reflection of placement

12. Thankyou for listening.
Are there any questions?