Science. NZQA Support Material Page 1 of 8. Unit standard version 1 Perform methods for animal tissue culture Level 6 Credits 5

Transcription

1 NZQA Support Material Page 1 of 8 Science Unit standard version 1 Perform methods for animal tissue culture Level 6 Credits 5 Assessor guidelines Candidate instructions Assessment task/s Assessment schedule

2 NZQA Support Material Page 2 of 8 Assessor guidelines This unit standard has two elements: Element 1 Prepare medium and seed with animal tissue. Element 2 Incubate and maintain cultures. Conditions 1 Practical assessment which will be assessed by laboratory book; laboratory practice by observation; final cultures which would include an assessment of the desired growth; contamination in cultures will be observed and noted if evident in candidate cultures. 2 It is recommended that Unit 8035, Carry out visualisation and measurement of microorganisms; Unit 8040, Perform aseptic laboratory techniques; and Unit 26117, Work safely in a science laboratory; or demonstrate equivalent knowledge and skills are completed before assessing this unit standard. 3 Holistic judgments could be made over a period of time in the programme of work by using the candidates work book or performance during practical sessions as an indicator of competency. It is expected the candidate will have met the standard by completing the technique successfully an X number of times. For the purpose of showing competency for a particular skill or technique in this standard X has been used. It is expected the assessor will determine the number of times a candidate would need to repeat the particular procedure to show competence. Typically this would be more than 3 times, however due to constraints with resources this would be specific to the provider. A simulated situation could be used to show competence, if applicable to the skill or technique. It is suggested that candidates learn the principles of dispensing media under aseptic conditions using water first and then progress to the more expensive culture media. It is suggested that the assessor has a checklist of tasks they expect to observe the candidate carrying out. This could be provided to the candidate in the teaching and learning prior to the assessment. The assessor could use this to judge competency. The principles of quality control in preparing media should be discussed with the candidates and the observation of candidates including appropriate quality assurance (QA) should be one of the items in the checklist of tasks that the assessor uses. Candidates should be made aware of good practices regarding retaining some of the parent cultures in case of sub-culture failure. The assessor will check/observe procedures during the culturing and inoculation process. Laboratory procedures must be followed and it is expected the candidates will have access to these so they are able to choose the appropriate techniques, labelling, storage, and incubation conditions for the tissue chosen. The assessor may use a checklist for QA for the procedure/s. This checklist would enable the judgment statements in the assessment schedule to be simplified.

3 NZQA Support Material Page 3 of 8 4 Health and Safety practices must conform to Australian/New Zealand Standard (AS/NZS) 2243 Set: 2006 Safety in Laboratories Parts 1, 2, 3, 7 and 10 available at and particularly part 3.

4 NZQA Support Material Page 4 of 8 Candidate instructions This assessment includes 3 tasks. Your assessor/tutor will assess your laboratory book; laboratory practice by observation; final cultures which would include an assessment of the desired growth; contamination in cultures will be observed and noted if evident in your cultures. Assessment task/s Task 1 and 2 Task 2 has an option: a Primary adherent animal tissue culture OR b Adherent immortalised tissue culture You may choose which option you wish to be assessed in or you will be directed by your assessor/tutor. Element 1 Prepare medium and seed with animal tissue. Task 1 Prepare media following laboratory procedures: follow the recipe for preparing the media (including ph, volume adjustments, labelling instructions or procedures); use and/or prepare sterile glassware and any other equipment to prepare the media; operate a sterile filtration unit; prepare the QA media required for sterility checks. Document relevant information in your laboratory notebook (e.g. weight/mass of dried media, ph adjustments, volumes etc.). Maintain sterility of media. Task 2 a (Primary adherent animal tissue culture) Prepare animal tissue for inoculation: prepare sterile equipment; prepare animal tissue for seeding e.g. macerate or tease tissue, and add enzymes for digestion of connective tissue; prepare the QA media required for sterility checks. Animal seed tissue to medium: transfer prepared tissue to culture medium aseptically e.g. into a tissue culture flask. OR

5 NZQA Support Material Page 5 of 8 b (Adherent immortalised tissue culture) Prepare animal tissue for inoculation: prepare sterile equipment; retrieve and thaw tissue culture; prepare the QA media required for sterility checks. Immortalised cells to medium: transfer prepared material to medium aseptically. Task 3 Element 2 Incubate and maintain cultures. Task 3 Incubate inoculated material in accordance with laboratory procedures: identify culturing conditions for the animal tissue used; placing of samples and quality control samples into the incubator. Document relevant information in your laboratory notebook as appropriate for the laboratory. These should include: labelling of cultures (passáge number as appropriate); incubation conditions (atmospheric, temperature, time); recording of position in the incubator; dates. Maintain and grow the animal cells: microscopic visualisation regularly as appropriate to laboratory; replenish the tissue culture with fresh media as required after analysis of the visualisation; split tissue culture as required.

6 NZQA Support Material Page 6 of 8 Assessment schedule Element 1 Prepare medium and seed with animal tissue. Range primary adherent, animal tissue culture OR adherent immortalized tissue culture. Performance criteria Evidence Judgment 1.1 Preparation of medium is carried out and sterility of medium confirmed in accordance with laboratory procedures. Observation of the candidate in the laboratory setting: Medium is chosen for animal tissue being seeded. Medium is prepared. ph adjustments are made and the ph is recorded. Recordings in the laboratory book: The animal tissue type chosen. Weight/mass used for amount of medium being made. ph adjustments made and ph readings. Procedure is carried out a minimum of X times. Medium is appropriate to tissue sample selected. Appropriate volume of media prepared. ph is recorded appropriate to the animal tissue sample selected. Sterility check shows no growth in medium. Labelling allows traceability. All above are completed in accordance with laboratory procedures.

7 NZQA Support Material Page 7 of Animal tissue is prepared and seeded on medium in accordance with laboratory procedures. Observation of the candidate in the laboratory setting: Preparation of tissue Seeding of tissue on medium.2 methods (primary or immortalised) are carried out. Procedure is carried out a minimum of X times: Method/procedures chosen is appropriate for type of animal tissue selected. Observation by assessor attests to sterile techniques. Uses sterile materials and techniques in accordance with the animal tissue. (primary or immortalised). (All above are completed in accordance with laboratory procedures). Element 2 Incubate and maintain cultures. Performance criteria Evidence Judgment 2.1 Inoculated medium is incubated in accordance with laboratory procedures. Observation of the candidate in the laboratory setting: Incubation conditions are chosen for the animal tissue. (e.g. temperature, humidity, atmosphere and time) Medium is incubated. Labelling for traceability. Procedure is carried out a minimum of X times: All conditions selected are appropriate to the material. Labelling allows traceability Assessor to determine sufficiency appropriate to availability of resources and animal tissue. (All above are completed in accordance with laboratory procedures).

8 NZQA Support Material Page 8 of Animal cells are grown in accordance with laboratory procedures. Observation of the candidate in the laboratory setting: Animal cells are grown. Procedure is carried out a minimum of X times: Un-inoculated medium incubated under same conditions as animal tissue material (QA). Un-inoculated medium has remained uncontaminated. Final cycle shows uncontaminated growth of original animal tissue selected. Replenishment is appropriate to animal tissue and visualization of the culture. Growth in all cycles is evident. At least 1 cycle for primary and 3 cycles for immortalised. Labelling allows traceability. (All above are completed in accordance with laboratory procedures).