The purity of target cells is low.
- The leukapheresis product was stored inappropriately. Pre pa ration
and separation of the leukapheresis product should be performed
immediately after leukapheresis. Keep the leukapheresis product at
a leukocyte concentration of less than 0.2
×
10
9
per mL. If necessary,
dilute the leukapheresis product with autologous plasma. The
leukapheresis product should not be older than 24 hours when
starting the labeling and separation procedure. If the leukapheresis
product has to be stored, e.g. overnight, it should be kept at controlled
room temperature (+19 °C to +25 °C [+66 °F to +77 °F]).
- The magnetic labeling protocol has not been followed (e.g., incorrect
volumes during magnetic labeling). Follow the instructions given for
the magnetic labeling (see chapter 4, STEP 1).
For troubleshooting purposes determine the leukocyte subsets
(B cells, T cells, monocytes, granulocytes as well as platelets)
contaminating the target cell fraction and contact Miltenyi Biotec
Technical Support for advice.
- High numbers of granulocytes contaminated the start product
(suboptimal apheresis setting). Dying granulocytes will then bind
the CliniMACS Reagent non-specifically which may lead to decreased
purity of the target cells.
- Valve malfunction occurred. Eluted target cell fraction has been
contaminated by part of the non-target fraction or buffer waste
fraction. Inspect tubing placement within the valves to ensure proper
functioning. Assess target cell content of the non-target cell fraction
and buffer waste. If necessary, pool the target and non-target cell
fraction, reduce to suitable volume and repeat the separation with a
new tubing set and sufficient new buffer.
- Elution from the separation column was incomplete.
• Separation program was aborted. Check display screen for
error message. Continue with section “Run is aborted before
completion of cell separation program” (see section 5.3).
• Pump failure or valve failure occured. Recover cells from the tubing
set following the EMERGENCY PROGRAM described in section 5.3.
Check volumes of all fractions. Assess target cell content of Buffer
Waste Bag and Negative Fraction Bag.
• Tubing to Cell Collection Bag is blocked. Check tubing set for
closed clamps, occlusions or kinks.
• Tubing has not been properly inserted. Check all valves for proper
tubing insertion.
37091/04 – ch20 (Issued: 2020-06)
CliniMACS® Plus System User Manual (Canadian edition)
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