Guidelines for the laboratory report on microbiology Homework Help

Guidelines for the laboratory report on microbiology

1650 words (excluding references).

The laboratory report should include the following:

• Title: Please provide a succinct, descriptive statement of the investigation.
  · Introduction:The aims of the investigation should be clearly stated in relation to previous research and experience. A review of relevant literature is normally a requirement. Always refer to literature sources in the past tense, e.g. Smith and Jones (2005)

found/reported/noted/observed/examined/studied etc.

• Materials and Methods
  A detailed account of the procedures used should be given in a concise form. You may use numbered sections and tables where appropriate. Sufficient detail should be given so that the work could be repeated independently.
  The method must be written in the past tense – it is an account of what you did, not a set of instructions for the future. If your account reads like a recipe book you are using the wrong style – and it is not usual to use the first person ‘I…’, ‘We…’ etc – it is not a diary of your experiences in the laboratory.
• Results and Discussion:
  Results must be presented clearly and discussed in the context of published work. The results should be displayed in tabular, diagrammatic and/or graphical form with explanatory text as required. All tables and figures (if any) should be individually numbered and titled. The titles for tables and figures must be sufficiently explanatory so that a reader can understand what is being presented from the table alone.
  Some people find it hard to decide what should be in the introduction and what should be in the discussion, but there is a simple rule. If you are writing about something you could have known from reading before conducting the study (i.e. it is received knowledge) it should be in the introduction. The discussion is a considered appraisal of the results – did the results agree or disagree with previous studies reported in the literature and why? What are the implications of the findings? Obviously if you are discussing your results in relation to the literature you will need to refer to it (as in the introduction). The validity and reliability of the methods and results should also be discussed including sources of error. It is usual to specify possible improvements to avoid any problems identified and to recommend future directions for the work. The final conclusions should be summarised concisely referring back to any hypotheses stated. What are the implications of your conclusions?
• References
  Background reading is essential and all references must be clearly cited in the text and listed at the end of the report. These must be arranged alphabetically by author. Several papers by the same author should be arranged chronologically. All the references listed should have been quoted in the text (and vice versa). Do not separately list books and journals, never use a numbered referencing system. Use primary research papers wherever possible.
  Use the Harvard referencing style – if you deviate from this or give incomplete bibliographic information (e.g. omit dates or page numbers) you will lose marks.
• Appendices
  This is the place to put raw data or additional material which is relevant but not essential to follow the main report. It is NOT the place to put results which are to be used or discussed in the main part of the report. These should go in the Results & discussion section. Beware – this is a common error.
• Literacy
  All of your work should be written in an appropriate scientific style and should be free from grammatical and spelling errors.

FORMATTING TIPS

• When writing your essay on microsoft word, make sure you select English (U.K.) as your main Language. This is also the language you must use when running spelling and grammar check.
• Please use these as standard guidelines when formatting your page: Margins: Left: 3cm, Right: 2cm, Top: 2cm Bottom: 2cm
  Spacing: 5 or double spacing
  Font: Arial, size 11
• Word count: include word count on first page.

FOOD MICROBIOLOGY PRACTICAL

Introduction

In order to grow microbes (e.g. bacteria), in the laboratory, nutrients, moisture and a suitable temperature must be provided. Microbes are normally cultured on nutrient agar plates (solid) or in nutrient broth (liquid) both of which provide the nutrients required by most microbes. Cultures are incubated at appropriates temperatures in an incubator and evidence of growth is usually visible after 24 hours.

FOOD MICROBIOLOGY PRACTICAL

• All agar plates must be clearly labelled with your name, the date and the experiment.
• Write on the underside of the plate using indelible ink, around the margin.

We will be trying to answer four questions relating to microbes in food, food safety and food handling:

1) Are microbes to be found everywhere in our environment?

2) Are microbes to be found in foods?

3)Are there microbes on the hands and does hand washing remove them?

4) Are microbes to be found on used dishcloths?

1) Are microbes to be found everywhere in our environment? (plug switch)

• Using a sterile swab, collect a sample from the site of interest. Return to the laboratory and gently streak the swab over a nutrient agar plate.
• Each person will take one sample.

2) Are microbes to be found in foods? (Yakult)

1. Take a sample (approximately half a teaspoon) from the food provided using forceps/spatula/scissors as appropriate.
2. Place the sample in a Universal bottle containing 5ml of diluent.
3. Mix thoroughly using a vortex mixer. Then, pipette 0.1 ml of sample from the bottle and gently spread it over the agar surface using a sterile spreader.
4. Each person will sample one food.

3) Are there microbes on the hands and does hand washing remove them?

1. Gently press the pads of the fingers of one hand onto a nutrient agar plate.
2. Wash hands and then repeat with the same hand.
3. Each person will sample a hand before and after washing.

4) Are microbes to be found on used dishcloths? (kitchen sponge)

1. Remove 0.2 ml of the sloth “extract” using an adjustable pipette and dispense onto a nutrient agar plate.
2. Spread this liquid evenly over the agar surface using a sterile spreader.
3. Each person will sample one cloth.

All plates must be inverted and placed in the incubator. They will be observed for evidence of microbial growth after one week.

FOOD MICROBIOLOGY / PRACTICAL: WEEK 2

Procedure

Pick off one individual colony using a sterile loop from plates and prepare a Gram stain of each on separate slides.

Slide preparation:

1. Put a drop (20 ?l) of sterile saline solution on a clean, labelled slide.
2. Take an individual colony as described above and mix gently with the saline solution.
3. Smear into a thin film using a sterile loop.
4. Dry the film in air and then pass through the top of a Bunsen flame, bacterial side up, to fix the smear. Do this very carefully (i.e. do not hold the slide in the flame) or the slide will heat up very quickly and crack.

Staining procedure:

1. Flood the slide with Gram stain 1 and leave for 1 minute.
2. Wash off the stain with water and flood the slide with Gram stain 2 and leave for 1 minute.
3. Wash in water and blot dry. Decolourise for 30 seconds by flooding the slide with 95% alcohol. Wash in water and blot dry.
4. Stain smear for 30 seconds with Gram stain 3.
5. Wash in water and blot dry. Observe under oil immersion (1000x magnification).

Bacterial cells should appear either Gram-positive (purple) or Gram-negative (pink). Record colour, cell shape and arrangement. Are there multiple types of bacterial cells present or only one type?

Results data to write microbial laboratory report:

The table below is an example. Provide result table something similar with pictures of the form of the bacteria. Also mention bacteria classification for each type either it is a gram positive or gram negative and the shape.

Example/ Table 1: Morphology, gram bacteria type and magnified microbial samples.